Further refactoring on ActionDisabledByAdminDialog classes.

Bug: 184107103
Bug: 188836559

Test: m -j RunSettingsRoboTests ROBOTEST_FILTER=ActionDisabledByAdminDialogHelperTest
Test: atest 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: I3c4056d82834b5e2a4afbd958be7c9d0b9af543e