Move NDK test modules into cc/testing.go

Move the NDK modules defined in app_test.go into cc/testing.go in
preparation for using sdk_version: "current" in more tests.

Test: all soong tests
Change-Id: I80bc31225fb4562fce42781219cefbbd6affae06

java/testing.go

@@ -18,6 +18,7 @@ import (
 	"fmt"
 
 	"android/soong/android"
+	"android/soong/cc"
 )
 
 func TestConfig(buildDir string, env map[string]string, bp string, fs map[string][]byte) android.Config {
@@ -52,8 +53,6 @@ func TestConfig(buildDir string, env map[string]string, bp string, fs map[string
 		"assets_a/a":             nil,
 		"assets_b/b":             nil,
 
-		"prebuilts/ndk/current/sources/cxx-stl/llvm-libc++/libs/arm64-v8a/libc++_shared.so": nil,
-
 		"prebuilts/sdk/14/public/android.jar":         nil,
 		"prebuilts/sdk/14/public/framework.aidl":      nil,
 		"prebuilts/sdk/14/system/android.jar":         nil,
@@ -122,6 +121,8 @@ func TestConfig(buildDir string, env map[string]string, bp string, fs map[string
 		"stubs/sources/foo/Foo.java": nil,
 	}
 
+	cc.GatherRequiredFilesForTest(mockFS)
+
 	for k, v := range fs {
 		mockFS[k] = v
 	}