apex: choose stub according to min_sdk_version

Native modules within APEX should be linked with proper stub version
according to its min_sdk_version.

For example, when min_sdk_version is set to "29", libfoo in the apex
would be linked to libbar of version 29 from platform, even if it has
a newer version like 30.

Bug: 145796956
Test: m nothing (soong tests)
Change-Id: I4a0b2002587bc24b7deeb5d59b6eeba5e1db5b1f

rust/rust.go

@@ -325,6 +325,10 @@ func (mod *Module) SetStubsVersions(string) {
 	panic("SetStubsVersions not yet implemented for rust modules")
 }
 
+func (mod *Module) StubsVersion() string {
+	panic("SetStubsVersions not yet implemented for rust modules")
+}
+
 func (mod *Module) BuildStaticVariant() bool {
 	if mod.compiler != nil {
 		if library, ok := mod.compiler.(libraryInterface); ok {