Revert "Add FlickerServiceRule to splitscreen platinum tests"

This reverts commit 339244f591418c5bef8a0c98c5aacf27bc161e5d.

Reason for revert: b/301407089 causing flakiness in other platinum tests (legacy flicker IME tests)

Bug: 301407089
Change-Id: I628a4c74371106fb6bcb21ab7f43fdbe1deca154
30 files changed