Refactored some ActionDisabledLearnMoreButtonLauncherImpl methods.

The interface they implement now takes a Context and Object instead
of Activity and AlertDialog.Builder.

Bug: 184107103
Bug: 188836559

Test: atest SettingsRoboTests:com.android.settings.enterprise.ActionDisabledLearnMoreButtonLauncherImplTest
Test: adb shell am start -e android.app.extra.RESTRICTION no_install_unknown-sources -a android.settings.SHOW_ADMIN_SUPPORT_DETAILS
Test: manual verification with CtsVerifier

Change-Id: Ifb08692f8b1973b8ffaeb98b29101b6a8f642922