Added notes on AbstractAdServicesFlagsSetterRule about using setFlags()

Bug: 300146214
Test: unfortunately not
Change-Id: I88a2c188f609d8e82eab4376f64cdfb99c0c1242
diff --git a/adservices/tests/test-util/side-less/com/android/adservices/common/AbstractAdServicesFlagsSetterRule.java b/adservices/tests/test-util/side-less/com/android/adservices/common/AbstractAdServicesFlagsSetterRule.java
index a8aa3ea..cb0d7ee 100644
--- a/adservices/tests/test-util/side-less/com/android/adservices/common/AbstractAdServicesFlagsSetterRule.java
+++ b/adservices/tests/test-util/side-less/com/android/adservices/common/AbstractAdServicesFlagsSetterRule.java
@@ -46,6 +46,11 @@
  * <p>Most methods set {@link android.provider.DeviceConfig} flags, although some sets {@link
  * android.os.SystemProperties} instead - those are typically suffixed with {@code forTests}
  */
+////////////////////////////////////////////////////////////////////////////////////////////////////
+// NOTE: DO NOT add new setXyz() methods, unless they need non-trivial logic. Instead, let your   //
+// test call setFlags(flagName) (statically import FlagsConstant.flagName), which will make it    //
+// easier to transition the test to an annotated-base approach.                                   //
+////////////////////////////////////////////////////////////////////////////////////////////////////
 abstract class AbstractAdServicesFlagsSetterRule<T extends AbstractAdServicesFlagsSetterRule<T>>
         implements TestRule {
 
@@ -362,7 +367,7 @@
     /**
      * Overrides flag used by {@link com.android.adservices.service.PhFlags#getPpapiAppAllowList()}.
      */
-    // <p> TODO (b/303901926) - apploy consistent naming to allow list methods
+    // <p> TODO (b/303901926) - apply consistent naming to allow list methods
     public T setPpapiAppAllowList(String value) {
         return setOrCacheFlag(FlagsConstants.KEY_PPAPI_APP_ALLOW_LIST, value, ALLOWLIST_SEPARATOR);
     }
@@ -429,6 +434,12 @@
         return setFlag(FlagsConstants.KEY_MDD_BACKGROUND_TASK_KILL_SWITCH, value);
     }
 
+    ////////////////////////////////////////////////////////////////////////////////////////////////
+    // NOTE: DO NOT add new setXyz() methods, unless they need non-trivial logic. Instead, let    //
+    // your test call setFlags(flagName) (statically import FlagsConstant.flagName), which will   //
+    // make it easier to transition the test to an annotated-base approach.                       //
+    ////////////////////////////////////////////////////////////////////////////////////////////////
+
     /**
      * Sets all flags needed to enable compatibility mode, according to the Android version of the
      * device running the test.
@@ -481,6 +492,12 @@
                 });
     }
 
+    ////////////////////////////////////////////////////////////////////////////////////////////////
+    // NOTE: DO NOT add new setXyz() methods, unless they need non-trivial logic. Instead, let    //
+    // your test call setFlags(flagName) (statically import FlagsConstant.flagName), which will   //
+    // make it easier to transition the test to an annotated-base approach.                       //
+    ////////////////////////////////////////////////////////////////////////////////////////////////
+
     /**
      * @deprecated only used by {@code CompatAdServicesTestUtils.resetFlagsToDefault()} - flags are
      *     automatically reset when used as a JUnit Rule.