Merge "Signed-off-by: Yusuke <yusuke.furuya@rakuten.com> Add: MMS config file for Rakuten Mobile MNO" am: 594aaaf10d am: bb219ee2ef am: ec4773c514 am: c5c95ab825

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

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I2eb7d40633515be2dbbd763e6e0a26eb5a702609