feat: implement app drawer and pin pad intents

[aaronkyriesenbach]

Resolves #712. Changes:

• Adds intent app.olauncher.ACTION_OPEN_APP_DRAWER to open the app drawer
• Adds intent app.olauncher.ACTION_DISMISS_KEYGUARD to pull up the pin pad on the lock screen (instead of swipe to unlock) - this was not part of the referenced issue, but is the exact same use case
• Changes the app name for debug builds to "Olauncher (Debug)" - I can revert this if you'd like, but it made it easier to work with while testing
• Updates README to document new intents

Tested working. To test, connect device with debug build installed via ADB and run:

adb shell am start -a app.olauncher.ACTION_OPEN_APP_DRAWER -n app.olauncher.debug/app.olauncher.MainActivity
adb shell am start -a app.olauncher.ACTION_DISMISS_KEYGUARD -n app.olauncher.debug/app.olauncher.MainActivity

App drawer should open and pinpad should open, respectively. (For release build, remove .debug from the above.)

The rest of the app has not been changed at all; it functions exactly the same as before. Please let me know if you have any questions or changes you'd like me to make, thanks!