Convert JavaInfoProvider to *JavaInfo

Convert JavaInfoProvider to return a *JavaInfo instead of a JavaInfo.
This will reduce copying when reading the provider, and also allows
JavaInfo to recursively contain a depset of JavaInfos from
dependencies.

Bug: 308016794
Test: go test ./java/...
Flag: EXEMPT refactor
Change-Id: Ibf6d9b797f760ad1fe815d59839839fdfad91733
diff --git a/java/system_modules.go b/java/system_modules.go
index 8e2d5d8..500d7fa 100644
--- a/java/system_modules.go
+++ b/java/system_modules.go
@@ -162,8 +162,9 @@
 	var jars android.Paths
 
 	ctx.VisitDirectDepsWithTag(systemModulesLibsTag, func(module android.Module) {
-		dep, _ := android.OtherModuleProvider(ctx, module, JavaInfoProvider)
-		jars = append(jars, dep.HeaderJars...)
+		if dep, ok := android.OtherModuleProvider(ctx, module, JavaInfoProvider); ok {
+			jars = append(jars, dep.HeaderJars...)
+		}
 	})
 
 	system.headerJars = jars