Update test_module_configs for split screen tests

Including

- Renaming files to comply with go/java-style#s5.2.2-class-names (test classes should end with Test)
- Updating manual configs for automatically generated ones for flicker tests

Bug: 311643481
Flag: TEST_ONLY
Test: atest WMShellFlickerTestsSplitScreen
Change-Id: Ic9fb1b9caf97dab082a7a5d3970564c23fc18bbe