Convert dex2oatPathFromDep to use ModuleProxy.

Bug: 377723687
Test: Unit tests and compare the ninja and mk files generated.
Change-Id: I99ffe88179991da8e5963605bf76666c8945d290
diff --git a/android/proto.go b/android/proto.go
index 66faa20..91d6732 100644
--- a/android/proto.go
+++ b/android/proto.go
@@ -75,7 +75,7 @@
 	}
 
 	ctx.VisitDirectDepsProxyWithTag(ProtoPluginDepTag, func(dep ModuleProxy) {
-		if h, ok := OtherModuleProvider(ctx, dep, HostToolProviderKey); !ok || !h.HostToolPath.Valid() {
+		if h, ok := OtherModuleProvider(ctx, dep, HostToolProviderInfoProvider); !ok || !h.HostToolPath.Valid() {
 			ctx.PropertyErrorf("proto.plugin", "module %q is not a host tool provider",
 				ctx.OtherModuleName(dep))
 		} else {