Add intent action and extra for managing a single default app.

This change adds Intent.ACTION_MANAGE_DEFAULT_APP and
Intent.EXTRA_ROLE_NAME for managing a single default app, which will
be launched from Settings' App info page. The new
Intent.EXTRA_ROLE_NAME also replaces RoleManager.REQUEST_ROLE_NAME.

Bug: 110557011
Test: build
Change-Id: Ice81150b0e960d050d24d963ade04254852a4ee4