Removes min_sdk_version from the apex blueprint

When com.android.virt sets min_sdk_version, all deps should set
min_sdk_version as well. However, it doesn't require min_sdk_version to
be set until it is supposed to be updatable. So rather than setting all
deps min_sdk_version to possibly wrong number, this change removes
min_sdk_version from the apex definition.

Bug: 177833148
Test: m com.android.virt
Change-Id: Idb1d492db995fe28bcf5ff1d60f2355e0bab01f1

apex/Android.bp

@@ -23,8 +23,6 @@ apex {
         },
     },
     binaries: ["assemble_cvd"],
-
-    min_sdk_version: "S",
 }
 
 apex_key {