Merge "Signed-off-by: Yusuke <yusuke.furuya@rakuten.com> Add: MMS config file for Rakuten Mobile MNO" am: 594aaaf10d

Original change: https://android-review.googlesource.com/c/platform/packages/apps/Messaging/+/1615180

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I518b5be8e5d6adff6c1cc8b4e3ffe5c943f22d3d