android: always on

[iwanbk]

• start on boot
• restart after being killed (in case of killed by Android)

related issue threefoldtech/mycelium#563

[iwanbk]

start on boot

Tried these things

• added the BrodcastReceiver https://developer.android.com/reference/android/content/BroadcastReceiver which listen to ACTION_BOOT_COMPLETED (android booted) and then start the TUN.
• store the key and peers to the shared preference, so it can be used later from the BroadcastReceiver

For unknown reason, the app keep crashing.

Suspect:
We have some initialization on the Dart side, i suspect that the initialization was not done properly without the app window opened.

Other problem:
The log is not reliable on this usecase, some logs are not printed.

[iwanbk]

It is on hold, based on threefoldtech/mycelium#563 (comment)

WIP: https://github.com/threefoldtech/myceliumflut/tree/android-on-boot