Guarded relevant call id API changes with flagging.

This change guards CallDetails#getId and StreamingCall#EXTRA_CALL_ID with the newly added telecom flag FLAG_CALL_DETAILS_ID_CHANGES.

Bug: 301713560
Test: Updated CallDetailsTest#testCallId and CallStreamingTest
Change-Id: I3819fa9eda5995d7ef354e71d2b4c7d5a4423e66
diff --git a/telecomm/java/android/telecom/Call.java b/telecomm/java/android/telecom/Call.java
index a7675d6..def52a5 100644
--- a/telecomm/java/android/telecom/Call.java
+++ b/telecomm/java/android/telecom/Call.java
@@ -942,6 +942,7 @@
          * @return the Telecom identifier associated with this {@link Call} . This is not a stable
          * identifier and is not guaranteed to be unique across device reboots.
          */
+        @FlaggedApi(Flags.FLAG_CALL_DETAILS_ID_CHANGES)
         public @NonNull String getId() { return mTelecomCallId; }
 
         /** {@hide} */
diff --git a/telecomm/java/android/telecom/StreamingCall.java b/telecomm/java/android/telecom/StreamingCall.java
index 29f436d..ad1b6f9 100644
--- a/telecomm/java/android/telecom/StreamingCall.java
+++ b/telecomm/java/android/telecom/StreamingCall.java
@@ -16,6 +16,7 @@
 
 package android.telecom;
 
+import android.annotation.FlaggedApi;
 import android.annotation.IntDef;
 import android.annotation.NonNull;
 import android.annotation.SystemApi;
@@ -25,6 +26,8 @@
 import android.os.Parcel;
 import android.os.Parcelable;
 
+import com.android.server.telecom.flags.Flags;
+
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 
@@ -57,6 +60,7 @@
     /**
      * The ID associated with this call.  This is the same value as {@link CallControl#getCallId()}.
      */
+    @FlaggedApi(Flags.FLAG_CALL_DETAILS_ID_CHANGES)
     public static final String EXTRA_CALL_ID = "android.telecom.extra.CALL_ID";
 
     /**