fstab.common: Mount external usb storage am: c98a9afbc5 am: de827eb203 am: 400ae7f5b6

Original change: https://android-review.googlesource.com/c/device/linaro/dragonboard/+/2875514

Change-Id: I4b6eeb19a6859cd6d127fa690a672905116463d4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>