This will help you with registering your package with AccessMgr

2.0 Steps required to allow remote control by Application
A number of steps are required to allow an application access to the remote control API.

Device needs to be provisioned to allow the application to bind to the Zebra service “com.zebra.eventinjectionservice” this involves using the AccessMgr CSP to allow the application permission to bind to the service.  Typically this is done when commissioning the device.
Runtime binding to the service by the application so that it can call the appropriate API.

2.1 Device provisioning
The device must be configured to allow the application access to the required zebra service. The signature of the application needs to be passed to the AccesMgr for access to be granted.
2.2 Getting Application signature
The application’s public certificate is required in a binary format for Stagenow or Base64 encoded if formatting the MX XML yourself for AccessMgr.  Typically this can be extracted from the keystore (if you have the passwords) or after the application has been installed using the Android Package Manger API.
Method 1
The signature can be extracted from the keystore using the JAVA tool “Keytool” and “OpenSSL” – these must be installed previously and are outside the scope of this document.
The command lines below will extract the public certificate from the Android keystore (remotecontrol.jks file in example) that was used to sign the certificate.
"C:\Program Files (x86)\Java\jre6\bin\keytool" -export -alias RC -file ..\certs\RemoteControl.der -keystore "D:\Android_AppStudioProjects\RemoteControlApplicationDemo\KeyStore\keystore.jks"
D:\openSSL\OpenSSL_Tools\openssl x509 -inform der -in ..\certs\RemoteControl.der -out ..\certs\RemoteControl.pem
D:\openSSL\OpenSSL_Tools\openssl x509 -outform der -in ..\certs\RemoteControl.pem -out ..\certs\RemoteControl.crt
Method 2
The certificate can be extracted using android API’s and the package manager. To do this an application or script will be required and the Remote Control application must be already installed. The code would be along the lines
    String sPackge = “Package name of the remote control application”
    final PackageManager pm = mContext.getPackageManager( ); Signature[] signatures = null; try { signatures = pm.getPackageInfo( sPackage, PackageManager.GET_SIGNATURES).signatures; if ( signatures != null ) { for (Signature sig : signatures) { final byte[] sigByte = sig.toByteArray() ; FileUtils.SaveDataToFile("/sdcard/RemoteControl.crt", sigByte ); } } } catch( Exception e ) { Log.v( TAG, "Exception Ssignatures Pck:" + sPackage + " Error:" + e.getMessage() ); } }
2.3 Allowing the Application Access to API
In order for the application to be allow access to the service that inject the keys the MX CSP “AccessMgr” must be configured to allow access.  The document assumes that you are familiar with the Zebra tool “StageNow” and using “Expert” mode.
First run StageNow and create a profile with MX 8.3 or above and add “AccessMgr” two times in “Xpert” mode.
On the first access manager screen enter the follow for each field

“Service Access Action” – select “Allow binding to service”
“Service Identifier” – enter “com.zebra.eventinjectionservice”

The screen should look similar to this

On the second access manager screen enter the follow for each field

“Service Access Action” – select “Allow caller to call service”
“Service Identifier” – enter “com.zebra.eventinjectionservice”
“Caller Package name” enter YOUR application package name
“Caller Signature” – select the certificate that you extract earlier for the application.  If using demo app select ..\Certs\RemoteControl.crt

The screen should look similar to this
 
Save the profile and display the Stagenow barcode.  Select the PDF417 barcode, staging client Stagenow then press “TEST” – barcode will be displayed as a PDF document – ensure Adobe Acrobat Reader DC is installed.
 
 
On the terminal run the Stagenow client and scan the barcodes (will be several) – this will pass the XML to the MX CSP and apply the XML.
You can save the XML to a file – use the “Export for MDM” option.
Your application should now have access to the service and be able to send key events.
You can also create the XML without using Stagenow and pass to the MX CSP either using the MDM tool kit or the EMDK profile manager – both require it is formatted correctly, note EMDK profile manager requires additional formatting.  It’s recommended that the MDM tool kit is used.
The MX XML format is documented please consult Zebra Tech Docs.  The format will be similar to that below which can be passed to the CSP via the MDM tool kit.

   
   
   

   
   
   
   
   

Note:
The “Characteristic version” must be at least 8.3.
Your certificate must the base64 encoded.
Should only need to change the items in bold italic text.

Update OS with latest Lifeguard patch and ensure the MX version is at least 8.3 - It will not work if below this.
Also you will need to register the signature of the package with AccessMgr - although this would only fail on the authenticate.

Thank you..that was really helpful.

Currently I am using a TC51 Oreo device with all the patch updates and MX version 8.4. In that I can't see the service running in settings-> apps.
Do we have a list of device models that are supported for this feature?

Yes it is correct.

Event injection service is available from MX 8.3 onwards.    
Please check in Apps & notifications -> AppInfo -> Show system ->EventInjectionService to confirm service exist in device.
Please find the attachment.

Can someone please advise where to find the documentation of the eventinjection service. I searched a lot here in the docs, but cannot find it

thx

Chris