Allows settings applications on other platforms to re-use values by
migrating to Settings.secure and moving HideNonSystemOverlayMixin to
SettingsLib.
Bug: 184967544
Test: atest SettingsUnitTests
Change-Id: If9aaeca29ebb8b481d75622934503e368d7435d3
This change do the 2 things:
1. Add new junit tests files which replace robolectric
RobolectricTestRunner & RuntimeEnvironment with
AndroidX objects without problem.
2. Remove the robolectric test files which have it's new junit files.
This change migrate 103 files, there are still 1209
files to go.
Bug: 174728471
Test: atest
make RunSettingsRoboTests
Change-Id: I15ed3f4745b85862f720aabbf710ce1475aced93