Fix test app and helper installation dirs.

Fixes: 143902486
Test: app_test.go + m CtsIsolatedSplitApp
Change-Id: I3e1b8bf14cb9f440a6d8b0d2ac65525f00470cb8
diff --git a/java/app_test.go b/java/app_test.go
index 2a4c4ec..7e461bc 100644
--- a/java/app_test.go
+++ b/java/app_test.go
@@ -1159,7 +1159,7 @@
 	}{
 		{
 			variantName:       "android_common",
-			apkPath:           "/target/product/test_device/testcases/foo_test/foo_test.apk",
+			apkPath:           "/target/product/test_device/testcases/foo_test/arm64/foo_test.apk",
 			overrides:         nil,
 			targetVariant:     "android_common",
 			packageFlag:       "",
@@ -1167,7 +1167,7 @@
 		},
 		{
 			variantName:       "android_common_bar_test",
-			apkPath:           "/target/product/test_device/testcases/bar_test/bar_test.apk",
+			apkPath:           "/target/product/test_device/testcases/bar_test/arm64/bar_test.apk",
 			overrides:         []string{"foo_test"},
 			targetVariant:     "android_common_bar",
 			packageFlag:       "com.android.bar.test",