*README.libaom: add 'Version' field

This field is required, but since the files are versioned with
'Revision', the field is marked as N/A [1]. Googletest is an exception,
since the revision refers to a release (1.12.1).

[1]: https://source.chromium.org/chromium/chromium/src/+/main:third_party/README.chromium.template;l=7;drc=94eb6ad26cf7ae0521408ff5430cdc269bcc85c6

Bug: 446258249, 460543970, 482449740, 482449718, 482449701
Bug: 482449277, 482450268
Change-Id: I5a1e4458482b45edc310270a19a2b030f169c55d

third_party/SVT-AV1/README.libaom

diff --git a/third_party/SVT-AV1/README.libaom b/third_party/SVT-AV1/README.libaom
index 9f0dc2e..069f7c1 100644
--- a/third_party/SVT-AV1/README.libaom
+++ b/third_party/SVT-AV1/README.libaom
@@ -1,5 +1,6 @@
 Name: SVT-AV1
 URL: https://gitlab.com/AOMediaCodec/SVT-AV1
+Version: N/A
 Update Mechanism: Manual
 Revision: 8ff99c90359330d2e807757c9425560bbc452ff3
 License: BSD-3-Clause-Clear

third_party/fastfeat/README.libaom

diff --git a/third_party/fastfeat/README.libaom b/third_party/fastfeat/README.libaom
index 770050b..2aab235 100644
--- a/third_party/fastfeat/README.libaom
+++ b/third_party/fastfeat/README.libaom
@@ -1,5 +1,6 @@
 Name: FAST feature detectors in C Version 2.0
 URL: https://github.com/edrosten/fast-C-src
+Version: N/A
 Update Mechanism: Manual
 Revision: 391d5e939eb1545d24c10533d7de424db8d9c191
 License: BSD-3-Clause

third_party/googletest/README.libaom

diff --git a/third_party/googletest/README.libaom b/third_party/googletest/README.libaom
index 16987ae..624c939 100644
--- a/third_party/googletest/README.libaom
+++ b/third_party/googletest/README.libaom
@@ -1,6 +1,7 @@
 Name: Google Test: Google's C++ Testing Framework
 Short Name: googletest
 URL: https://github.com/google/googletest
+Version: 1.12.1
 Update Mechanism: Manual
 Revision: release-1.12.1
 License: BSD-3-Clause

third_party/highway/README.libaom

diff --git a/third_party/highway/README.libaom b/third_party/highway/README.libaom
index b1a83ba..7fc5db9 100644
--- a/third_party/highway/README.libaom
+++ b/third_party/highway/README.libaom
@@ -1,6 +1,7 @@
 Name: Highway: C++ library for SIMD
 Short Name: highway
 URL: https://github.com/google/highway
+Version: N/A
 Update Mechanism: Manual
 Revision: e92c12750d18c372867809b882dd3ec6874ecc73
 License: BSD-3-Clause

third_party/libwebm/README.libaom

diff --git a/third_party/libwebm/README.libaom b/third_party/libwebm/README.libaom
index 49a6bbe..850b9ce 100644
--- a/third_party/libwebm/README.libaom
+++ b/third_party/libwebm/README.libaom
@@ -1,5 +1,6 @@
 Name: libwebm
 URL: https://chromium.googlesource.com/webm/libwebm
+Version: N/A
 Update Mechanism: Manual
 Revision: 3b630045052e1e4d563207ab9e3be8d137c26067
 License: BSD-3-Clause

third_party/libyuv/README.libaom

diff --git a/third_party/libyuv/README.libaom b/third_party/libyuv/README.libaom
index 84ae660..cdf1652 100644
--- a/third_party/libyuv/README.libaom
+++ b/third_party/libyuv/README.libaom
@@ -1,5 +1,6 @@
 Name: libyuv
 URL: https://chromium.googlesource.com/libyuv/libyuv/
+Version: N/A
 Update Mechanism: Manual
 Revision: dfaf7534e0e536f7e5ef8ddd7326797bd09b8622
 License: BSD-3-Clause

third_party/vector/README.libaom

diff --git a/third_party/vector/README.libaom b/third_party/vector/README.libaom
index 609097d..f8e06b0 100644
--- a/third_party/vector/README.libaom
+++ b/third_party/vector/README.libaom
@@ -1,5 +1,6 @@
 Name: vector
 URL: https://github.com/goldsborough/vector
+Version: N/A
 Update Mechanism: Manual
 Revision: 40efe82
 License: MIT

third_party/x86inc/README.libaom

diff --git a/third_party/x86inc/README.libaom b/third_party/x86inc/README.libaom
index 6d6e256..d6f8901 100644
--- a/third_party/x86inc/README.libaom
+++ b/third_party/x86inc/README.libaom
@@ -1,5 +1,6 @@
 Name: x86inc.asm
 URL: https://git.videolan.org/git/x264.git
+Version: N/A
 Update Mechanism: Manual
 Revision: 3e5aed95cc470f37e2db3e6506a8deb89b527720
 License: ISC