toolchain: Switch back to tracked revisions on Android

This allows us to recreate the entire LVL package from any point in history.
We continue to pull known good revisions from AOSP.
diff --git a/build-android/glslang_revision_android b/build-android/glslang_revision_android
index 1f7391f..a81a930 100644
--- a/build-android/glslang_revision_android
+++ b/build-android/glslang_revision_android
@@ -1 +1 @@
-master
+7fb605aeb525728edc23aaf3d3fd0ce08a6df95b