Restore lost .dm support of adb install-multiple

Apparently some changes are lost in
https://android-review.googlesource.com/c/platform/system/core/+/600457.

Test: adb install-multiple foo.apk foo.dm
Bug: 117092647
Change-Id: I87a6e1509de809624254c77073d922617f222ed2
1 file changed