Make gradle build use debuggable FeatureFlagManager

Fixes: 204129347
Test: gradle build & dump
Change-Id: I06ba95f4cc21b06519e676afee4bb6ae9c44c03e
diff --git a/packages/SystemUI/Android.bp b/packages/SystemUI/Android.bp
index c6cca5a..721b432 100644
--- a/packages/SystemUI/Android.bp
+++ b/packages/SystemUI/Android.bp
@@ -52,12 +52,18 @@
 
 filegroup {
     name: "ReleaseJavaFiles",
-    srcs: ["src/com/android/systemui/flags/FeatureFlagManager.java"],
+    srcs: [
+        "src-release/**/*.kt",
+        "src-release/**/*.java",
+    ],
 }
 
 filegroup {
     name: "DebugJavaFiles",
-    srcs: ["src-debug/com/android/systemui/flags/FeatureFlagManager.java"],
+    srcs: [
+        "src-debug/**/*.kt",
+        "src-debug/**/*.java",
+    ],
 }
 
 android_library {
@@ -66,6 +72,8 @@
         "src/**/*.kt",
         "src/**/*.java",
         "src/**/I*.aidl",
+        "src-release/**/*.kt",
+        "src-release/**/*.java",
     ],
     product_variables: {
         debuggable: {
@@ -159,6 +167,8 @@
         "src/**/*.kt",
         "src/**/*.java",
         "src/**/I*.aidl",
+        "src-release/**/*.kt",
+        "src-release/**/*.java",
     ],
     static_libs: [
         "SystemUIAnimationLib",