Revert "first_stage_mount: Bind mount /system after switch root"

This reverts commit d7e6353a69f6cc0b66198eb0a2726abe0f655dcb.

Reason for revert: b/239574953 breaking emulator based test on g3

Change-Id: Ib7d17fe8383937c7764f6612cf89db4fb7e5a4d3
1 file changed