Fix  PreservedSettingsRestoreTest

1. The preserve settings feature is now guarded by a flag. Enable it before
   running PreservedSettingsRestoreTest and disable after.
2. Change the values for accessibility_captioning_font_scale to be
   floats. Otherwise they don't pass validation and don't get restored
   making this test a no-op.

Test: atest PreservedSettingsRestoreHostSideTest
Change-Id: I093e42261719689dcb6e349026a81ba81d44b763
1 file changed