After much wrangling of my Android Studio, I got the source code in the tutorial here (http://techdocs.zebra.com/emdk-for-android/6-9/tutorial/tutBasicScanningAPI/) to build and deploy. The main activity shows up with the message "The scanner enabled and its idle", which is not what I expected. Further, pressing the hard triggers didn't do anything. But if I then open the DWDemo that came with the phone, select a scanner (I can even reselect the current option), and then switch back to my test app, the light flashes and I scan. I have debugged the code with a breakpoint where the scanner is assigned, but there I couldn't find any obvious field that would tell me about the scanner's status (whether idle or not).
Android Version: 7.1.2
EMDK Version: 6.9
Full disclosure: I am actually playing with this with the intention of incorporating it into a Cordova (Angular/Ionic) app. This is the first step, as once I can get the scanner to work (or be programmatically turned 'on'), I can create a plugin. If anyone knows of a plugin that works for Cordova and the TC25, please do let me know.