[codehealth] Fix third-party metadata for googletest, libcxx, and libcxxabi

Added the missing README.chromium file for googletest with the
necessary 'Security Critical', 'Version', and 'Revision' fields.

Renamed README.openscreen to README.chromium for libc++ and libc++abi
to match standard Chromium project guidelines, and added their missing
'Revision' fields based on their current submodule SHAs.

This resolves automated metadata tracking issues.

Fixed: 511607099, 511607634, 511607185
Change-Id: I555195db0edbbc2952bbe2554d557974d2065c03
Reviewed-on: https://chromium-review.googlesource.com/c/openscreen/+/7857615
Commit-Queue: Mark Foltz <mfoltz@chromium.org>
Reviewed-by: Mark Foltz <mfoltz@chromium.org>

PRESUBMIT.py

diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 231414c..7a6842a 100755
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -56,6 +56,7 @@
         os.path.join('third_party', 'rust-toolchain'),
         os.path.join('third_party', 'depot_tools'),
         os.path.join('third_party', 'boringssl', 'src', 'third_party'),
+        os.path.join('third_party', 'getopt'),
         os.path.join('third_party', 'googleurl', 'src', 'polyfills',
                      'third_party'),
         os.path.join('third_party', 'instrumented_libs', 'binaries'),

third_party/googletest/README.chromium

diff --git a/third_party/googletest/README.chromium b/third_party/googletest/README.chromium
index 81db16f..fa79a4b 100644
--- a/third_party/googletest/README.chromium
+++ b/third_party/googletest/README.chromium
@@ -1,5 +1,12 @@
 Name: googletest
+Short Name: googletest
 URL: https://github.com/google/googletest
+Version: 1.8.0
+Revision: eb2d85edd0bff7a712b6aff147cd9f789f0d7d0b
 License: BSD-3-Clause
 License File: src/LICENSE
+Security Critical: no
 Shipped: no
+
+Description:
+Google's framework for writing C++ tests on a variety of platforms.

third_party/libc++/README.chromium

diff --git a/third_party/libc++/README.chromium b/third_party/libc++/README.chromium
index 85c7eea..29a80dd 100644
--- a/third_party/libc++/README.chromium
+++ b/third_party/libc++/README.chromium
@@ -2,6 +2,7 @@
 Short Name: libc++
 URL: http://libcxx.llvm.org/
 Version: 1.0
+Revision: 07572e7b169225ef3a999584cba9d9004631ae66
 License: NCSA, Apache-with-LLVM-Exception, MIT
 License File: src/LICENSE.TXT
 Security Critical: yes

third_party/libc++abi/README.chromium

diff --git a/third_party/libc++abi/README.chromium b/third_party/libc++abi/README.chromium
index e6eea11..0f804e5 100644
--- a/third_party/libc++abi/README.chromium
+++ b/third_party/libc++abi/README.chromium
@@ -2,6 +2,7 @@
 Short Name: libc++abi
 URL: http://libcxxabi.llvm.org/
 Version: 1.0
+Revision: 83a852080747b9a362e8f9e361366b7a601f302c
 License: NCSA, Apache-with-LLVM-Exception, MIT
 License File: src/LICENSE.TXT
 Security Critical: yes