Add a common interface for cc linkable libraries.

Adds an interface, CcLinkableInterface, for cc linkable dependencies
which come from other toolchains such as Rust.

Bug: 140726209
Test: Soong tests pass, rust modules still compile.
Change-Id: I7378a46fad94fd0b735746aaf4e265fd2c2c04d8
diff --git a/cc/vndk.go b/cc/vndk.go
index 2997204..b066439 100644
--- a/cc/vndk.go
+++ b/cc/vndk.go
@@ -98,7 +98,7 @@
 	return "native:vendor:vndkspext"
 }
 
-func (vndk *vndkdep) vndkCheckLinkType(ctx android.ModuleContext, to *Module, tag dependencyTag) {
+func (vndk *vndkdep) vndkCheckLinkType(ctx android.ModuleContext, to *Module, tag DependencyTag) {
 	if to.linker == nil {
 		return
 	}