[automerger skipped] Merge "[DO NOT MERGE] Set RBE_DIR default value to point...

[automerger skipped] Merge "[DO NOT MERGE] Set RBE_DIR default value to point to prebuilts in tree." into qt-dev am: d9cf148d am: 4f66e757 -s ours am: f473b50e -s ours am: 45ec8a4f -s ours

am skip reason: subject contains skip directive

Original change: https://googleplex-android-review.googlesource.com/c/platform/build/+/12593960

Change-Id: I5653486da04a7d35ad34ff84b8da7f176b21cf40