NOTE: this is only compiled into products with PRODUCT_IOT=true.
Introduce BootActions that a developer can provide to manipulate IO
before the android framework comes up on boot.
We will look for a configuration file at /oem/app/etc/boot_action.conf and
expect it to tell us the name of a shared library. We will then fetch
this library from /oem/app/lib/${arch}/ and load it. We expect it to export
boot_action_init(), boot_action_shutdown(), and optionally
boot_action_start_part(int partNumber, int playNumber).
We will then call boot_action_init() during boot after PeripheralManager
is up and call boot_action_shutdown() when the android framework is up
and we are going to start loading APKs.
We will also call boot_action_start_part(*) when each part of the boot
animation is started, use this if you want to synchronize the boot
action and the boot animation.
Boot actions run in a restricted environment and in general can only
make calls to PeripheralManager.
Bug: 37992717
Test: Pushed to local imx7d to test boot actions, pushed to bullhead test that animation+sound still works.
Change-Id: I9e53a17567f8028ea84486d637e1d231ee1125e1