[automerge] Update fastboot version checking to 3103 to support P21 2p: 2573c7ce0a am: 56d83740c9 am: 863f4b33ac

Original change: https://googleplex-android-review.googlesource.com/c/device/common/+/15720117

Change-Id: Ia0ce9ae1ce999616c55ccf564ce3d7155fbf26fa