Fix DevicePolicyManager setTime() behavior / tests

Fix DevicePolicyManagerService setTime() behavior and associated CTS
tests. Since change ID If48d465fce04c094a997b25c8b62fcf0c3386ebe,
DevicePolicyManagerService calls TimeDetector.suggestManualTime().
Before doing so it clears client permissions so it is reliant on system
server permissions. The permission check for suggestManualTime() should
therefore be a enforceCallingOrSelfPermission() not a
enforceCallingPermission().

Bug: 145508391
Bug: 140712361
Test: atest com.android.cts.devicepolicy.DeviceOwnerTest#testSetTime
Change-Id: I20678e145127fd67f356f1c29abc30b484278231