Rolling ANGLE into AOSP requires the following fixes:

1.) Update scripts/roll_aosp.sh to not delete third_party/abseil-cpp.
2.) Update BUILD.gn to add a dependency on libnativewindow for
"angle_common".

Test: AOSP Presubmit
Bug: angleproject:5230
Change-Id: If97c44ce041e576edc7c0c43700030b4538e8ab5
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2495550Reviewed-by: Tim Van Patten <timvp@google.com>
Commit-Queue: Tim Van Patten <timvp@google.com>