Add pirama to OWNERS am: aae2059443 am: 795a278f7b

Original change: https://android-review.googlesource.com/c/platform/external/libcxx/+/3046252

Change-Id: Id34e741565cf3cba47da336c7f972cfdacb01c83
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>