Merge "Add FLAG_IMMUTABLE to PendingIntent in LegacyModeSmsHandler." into pi-dev am: 44b02956 am: 06572a08 am: 5625595e am: 0642423c am: 30d5474b am: e178da49 am: 44b61e5d

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Dialer/+/16199731

Change-Id: I1419d34efc783bdbace77fd5120936865607f415