Fix cloud provider todos for Android T

Added official support for app developers to set a cloud provider
with:

adb shell device_config put storage_native_boot
allowed_cloud_providers com.example.cloudmediaprovidersample.provider

The old method using set_cloud_provider still works just for CTS. This
will be removed in a subsequent cl

Test: Manual
Bug: 232457261
Change-Id: Id9c430324024a4c4b6bfb4d9ec122b4c73bf5dbf
5 files changed