Add InCallService docs to state prerequisites for be being a dialer app.

The InCallService documentation does not clearly state that an app which
wants to become the default dialer app also needs to handle the DIAL
intent.  This change updates the documentation to make this clear.

Test: Built documentation and verified its contents.
Bug: 72857373
Change-Id: I738a8475df37035a0a7f4ad1639df76d967f81dc

1 files changed, 20 insertions, 0 deletions

diff --git a/telecomm/java/android/telecom/InCallService.java b/telecomm/java/android/telecom/InCallService.java
index fcf04c9a7eef..af65c65a48b7 100644
--- a/telecomm/java/android/telecom/InCallService.java
+++ b/telecomm/java/android/telecom/InCallService.java
@@ -60,6 +60,26 @@ import java.util.List;
  * </service>
  * }
  * </pre>
+ * <p>
+ * In addition to implementing the {@link InCallService} API, you must also declare an activity in
+ * your manifest which handles the {@link Intent#ACTION_DIAL} intent.  The example below illustrates
+ * how this is done:
+ * <pre>
+ * {@code
+ * <activity android:name="your.package.YourDialerActivity"
+ *           android:label="@string/yourDialerActivityLabel">
+ *      <intent-filter>
+ *           <action android:name="android.intent.action.DIAL" />
+ *           <category android:name="android.intent.category.DEFAULT" />
+ *      </intent-filter>
+ * </activity>
+ * }
+ * </pre>
+ * <p>
+ * When a user installs your application and runs it for the first time, you should prompt the user
+ * to see if they would like your application to be the new default phone app.  See the
+ * {@link TelecomManager#ACTION_CHANGE_DEFAULT_DIALER} intent documentation for more information on
+ * how to do this.
  */
 public abstract class InCallService extends Service {