Make changes to Settings Spa tests compatible with RNG.

This CL makes necessary changes to Spa tests for bivalent test running
(i.e. both device and deviceless test runs).

Bug: 300278210
Test: atest -c SpaRoboRNGTests (http://ab/I96000010215772062)
Change-Id: Ibb8657da5767ee975ddbbc9f2452aa503bd01900
diff --git a/packages/SettingsLib/Spa/screenshot/Android.bp b/packages/SettingsLib/Spa/screenshot/Android.bp
index bd508cb..dbf4ce0 100644
--- a/packages/SettingsLib/Spa/screenshot/Android.bp
+++ b/packages/SettingsLib/Spa/screenshot/Android.bp
@@ -18,6 +18,14 @@
     default_applicable_licenses: ["frameworks_base_license"],
 }
 
+filegroup {
+    name: "SpaScreenshotTestRNGFiles",
+    srcs: [
+        "src/**/*.java",
+        "src/**/*.kt",
+    ],
+}
+
 android_test {
     name: "SpaScreenshotTests",
     use_resource_processor: true,
@@ -36,6 +44,7 @@
         "androidx.test.ext.junit",
         "androidx.test.runner",
         "mockito-target-minus-junit4",
+        "platform-parametric-runner-lib",
         "platform-screenshot-diff-core",
     ],
     kotlincflags: ["-Xjvm-default=all"],