Add new default interface.

Bug: 79701706
Test: tap
PiperOrigin-RevId: 198747775
Change-Id: I3bd0d26ee6621ebe428e4e8c82b51959d313608f
diff --git a/java/com/android/incallui/speakeasy/SpeakEasyCallManager.java b/java/com/android/incallui/speakeasy/SpeakEasyCallManager.java
index b060f64..f2916f4 100644
--- a/java/com/android/incallui/speakeasy/SpeakEasyCallManager.java
+++ b/java/com/android/incallui/speakeasy/SpeakEasyCallManager.java
@@ -54,6 +54,16 @@
    */
   boolean isAvailable(@NonNull Context context);
 
+  /**
+   * Optional: Performs work necessary to happen-before callers use other methods on this interface.
+   *
+   * @apiNote Use of this API is completely optional, and callers are NOT required to invoke this
+   *     method prior to using other methods on the interface.
+   * @implSpec Other members of this interface always promise to do any required initialization work
+   *     at the time they are invoked. This method will always be idempotent.
+   */
+  default void performManualInitialization() {}
+
   /** Returns the config provider flag associated with the feature. */
   @NonNull
   String getConfigProviderFlag();