Check intent null before calling

Bug: 413766370
Test: TreeHugger
Test: manual
Test: atest SafetySourceBroadcastReceiverTest
Test: atest LockScreenSafetySourceTest
Test: atest ActiveUnlockStatusUtilsTest
Test: atest WearSafetySourceTest
Flag: com.android.settings.flags.biometrics_onboarding_education
Change-Id: Ifff4ce2d33d56e001bf800ecc1ec357273ceeaf9