More clearly document Android API/contract differences from stock Android

[mcomella]

Why/User Benefit/User Problem

There are some differences in how Echo Show uses the Android APIs/contracts from stock Android (for example, the conditions under which we timeout and the OS' way of killing our app). These differences may make it hard for developers to switch over to developing FFES, e.g. from FFTV.

While these differences are often documented in code comments when they're relevant, we should consider making a master list of known differences to improve the speed of onboarding, e.g. when fixing new issues that involve these API differences. We document some but we can be more explicit.

What / Requirements

• Go through code comments (e.g. multi-paragraph comments) to identify differences in development
• Look at existing list
• Compile differences in new document aimed at onboarding devs at working on FFES

Acceptance Criteria (how do I know when I’m done?)

• User test: verify with FFES devs (Severin) and non-FFES devs if the content makes sense

[mcomella]

@athomasmoz FYI: if dnarcese starts working on FFES, it might be good to do this sooner rather than later.