Add FlickerTestsIme to platinum

it's used in v2/android-platinum/suite/test-mapping-staged-platinum

Change-Id: I87d9aff0dea6344908e44ed693730143f504dbf8
Test: presubmit
Bug: 341947105

tests/FlickerTests/IME/Android.bp

@@ -38,6 +38,10 @@ android_test {
     defaults: ["FlickerTestsDefault"],
     manifest: "AndroidManifest.xml",
     test_config_template: "AndroidTestTemplate.xml",
+    test_suites: [
+        "device-tests",
+        "device-platinum-tests",
+    ],
     srcs: ["src/**/*"],
     static_libs: ["FlickerTestsBase"],
     data: ["trace_config/*"],