Drop runtime apex deps from implicit baselineApexAvailable map

The availability of these soong modules to com.android.runtime has
been made explicit in Android.bp files

One exception is libz. Making apex_available explicit has some subtle
implications on stub/impl selection which breaks coverage builds.

Bug: 281077552
Test: m nothing
Change-Id: I6db7db6dfcb5c468ca68c3e166fe79b9356c4fa8