Refactor the build rules for ABI diff

- Move the logic that determines the versioned dump directories
  from pathForVndkRefAbiDump to linkSAbiDumpFiles.
- Move sourceAbiDiff which generates the flags for ABI diff from
  builder.go to library.go.
- Define two functions that generate the rules for cross-version and
  same-version ABI diff.

Bug: 227282691
Test: make
Change-Id: Ic33799e86dd9ae627f5680b70973f96e15c030e9