Rename bzl files to scl

These files don't have anything to do with bazel, they just use starlark as a configuration
language. Bazel recently introduced the scl file extension to use for this format, which doesn't
have any bazel-specific symbols. Use that extension for our pure starlark files as well.

Bug: 309686282
Test: Presubmits
Change-Id: Ic17eff0b97bcb7584a7f9afaef2e470887362e18
7 files changed
tree: a9173e699a82722ba2ba99096599eac2b849f970
  1. aconfig/
  2. build_config/
  3. build_flags.scl
  4. OWNERS
  5. release_config_map.mk