[Manual] Fix static field names

* Run 'static' field naming convention inspection in Intellij
* Use regex s[A-Z][A-Za-z\d]*, the same one in CheckStyle
* Change non-public variable names to sCamelCase
* Add final modifier to constants

Bug: 63597465
Test: make checkbuild, no functional changes
Change-Id: I395bf3e11c2932b36cda471ca088dc5345b0f378