Updated strings and removed some obsolete strings that were no longer
used. Removed unusued instance variable in AppStateInstallAppsBridge
Test: Manual
Bug: 36454399
Change-Id: I858bb388f311fd012527500cf35255d191b4dfb7
Added a preference link to manage external sources in the app info
screen just like other special access permissions.
Test: Manually checked that the link appears on apps once their app op
is set to allow or deny.
Also, added some basic robolectric unit tests:
make -j32 RunSettingsRoboTests
Bug: 35481942
Change-Id: If687778b7a64fb7d278508b78d06272253a98e3e
Added a settings fragment to manage external sources. It lists all
applications that have either requested REQUEST_INSTALL_PACKAGES or have
their app op changed from default.
Test: Will include in follow-up CL. Tracked in b/33792674
Bug: 31002700
Change-Id: Ibd2a1922be214b62aec4eefa45f7b9691256b205