Refactor backported_fixes rules to share with cts

The sharable rules include

proto libary and file
Combining BackportedFix files
Converting BockportedFix text protos to binary protos

Test: atest backported_fixes_main_lib_test backported_fixes_common_test
Bug: 375460641
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:13a26b80a4250ff54bc6364ea01e1b9ede8558f5)
Merged-In: Ie75ede120d5555119ad265e4def728af9535bb1f
Change-Id: Ie75ede120d5555119ad265e4def728af9535bb1f