Refactor One handed mode Unit tests

1) Fix all broken tests and use mock for unit tests
2) Integrate TestableContext for unit tests
3) Do not update/restore Settings from TestBase
4) Limit to grant permissions for test cases

Fixes: 167943723
Test: atest WMShellUnitTests
Change-Id: Id02aa26e63b96962d955fcfbf061d668a6cb731c
13 files changed