Set legacy_android10_support to apex modules

media/swcodec apexes should support Android 10.
With this flag, apex packages will include older APEX manifest format
(JSON) as well as new format (Protobuf) so that they will work with
Android 10.

Bug: 143951586
Test: m com.android.media com.android.media.swcodec
      and install these to Android Q device
Change-Id: I927a464a8c7b88060126db398f568720396847f0