Upstread the AOSP license changes that keep getting reverted:
https://android-review.googlesource.com/c/platform/external/angle/+/1704346

Added SPDX-license-identifier-Apache-2.0 SPDX-license-identifier-BSD to:
  third_party/android_ndk/sources/android/cpufeatures/Android.mk

Added SPDX-license-identifier-Apache-2.0 SPDX-license-identifier-BSD
    SPDX-license-identifier-GPL SPDX-license-identifier-GPL-2.0
    SPDX-license-identifier-GPL-3.0 SPDX-license-identifier-LGPL
    SPDX-license-identifier-MIT SPDX-license-identifier-Zlib
    legacy_unencumbered
to:
  Android.bp via generate_android_bp.py

Bug: b/186906888
Change-Id: I86081cfe2858702ed350ce8c72afaaa8eb5566b8
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2912918Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Tim Van Patten <timvp@google.com>