Add content description to few missing places

[Stypox]

Addresses points 1 and 2 of issue #325.

I am not sure how to handle point 3 yet, there are too many buttons around the app and most of them already explain what is supposed to happen when you tap on them, so adding onClick semantics feels redundant. For example, I think it's better if, when the microphone button is focused, the talkback said "Start listening button, double tap to activate" instead of "Start listening button, double tap to start listening". The latter feels redundant. https://github.com/zhou-zhoukang can you help me pinpoint in which places it would be helpful to add onClick semantics?

Debug APK: https://github.com/Stypox/testing-apks/releases/download/16/app-debug.apk

[zhou-zhoukang]

I have seen the new APK. Thank you for your effort, all the issues have been resolved, and it looks very good.

Regarding the onClick Label, it's true that it's not always necessary when the button already has descriptive text.

[Stypox]

Thanks for the feedback!