Add new build flag for Khmer font update Bug: 381019613 Test: Manually done Test: build-flag --all-releases get RELEASE_PACKAGE_NOTO_SANS_KHMER_VERSION Flag: RELEASE_PACKAGE_NOTO_SANS_KHMER_VERSION Ignore-AOSP-First: AOSP is not ready for flagging Change-Id: Ic47d42e8d6b5aabbd16dc3ed2c361b23d62f8e8f