Fix DialerSettingsActivity so it does not crash pre-M.

UserManager.isSystemUser() is not available pre-M, so we need to copy
over the logic.

Bug: 25776171
Change-Id: I8e7c8e7215a8b55009283ecb137cc54443e61ab8
2 files changed
tree: 00a1a86061d841d918548218247621907416237a
  1. res/
  2. src/
  3. tests/
  4. Android.mk
  5. AndroidManifest.xml
  6. proguard.flags