cmsdk: Mandate telephony feature xml's for service implementation.

The feature xml plays two roles:

      1) To allow sdk interface (constructor) to throw when system
      service is unavailable. This allows for clearer platform
      development debugging.

      2) To allow for simpler disambiguation of what services to
      instrument in a modular environment.

Change-Id: Ib8e41130f143f784088b4566589a4ddc58aa2ace
TICKET: CYNGNOS-2291

cm/lib/main/java/org/cyanogenmod/platform/internal/CMTelephonyManagerService.java

@@ -186,8 +186,13 @@ public class CMTelephonyManagerService extends SystemService {
         if (localLOGD) {
             Log.d(TAG, "CM telephony manager service start: " + this);
         }
+        if (mContext.getPackageManager().hasSystemFeature(
+                CMContextConstants.Features.TELEPHONY)) {
             publishBinderService(CMContextConstants.CM_TELEPHONY_MANAGER_SERVICE, mService);
-
+        } else {
+            Log.wtf(TAG, "CM telephony service started by system server but feature xml not" +
+                    " declared. Not publishing binder service!");
+        }
         mTelephonyManager = (TelephonyManager) mContext.getSystemService(Context.TELEPHONY_SERVICE);
     }
 

src/java/cyanogenmod/app/CMContextConstants.java

@@ -149,5 +149,13 @@ public final class CMContextConstants {
          */
         @SdkConstant(SdkConstant.SdkConstantType.FEATURE)
         public static final String APP_SUGGEST = "org.cyanogenmod.appsuggest";
+
+        /**
+         * Feature for {@link PackageManager#getSystemAvailableFeatures} and
+         * {@link PackageManager#hasSystemFeature}: The device includes the cm telephony service
+         * utilized by the cmsdk.
+         */
+        @SdkConstant(SdkConstant.SdkConstantType.FEATURE)
+        public static final String TELEPHONY = "org.cyanogenmod.telephony";
     }
 }

src/java/cyanogenmod/app/CMTelephonyManager.java

@@ -26,6 +26,8 @@ import android.util.Slog;
 
 import java.util.List;
 
+import cyanogenmod.app.CMContextConstants;
+
 /**
  * The CMTelephonyManager allows you to view and manage the phone state and
  * the data connection, with multiple SIMs support.
@@ -55,6 +57,13 @@ public class CMTelephonyManager {
             mContext = context;
         }
         sService = getService();
+
+        if (context.getPackageManager().hasSystemFeature(CMContextConstants.Features.TELEPHONY)
+                && sService == null) {
+            throw new RuntimeException("Unable to get CMTelephonyManagerService. " +
+                    "The service either crashed, was not started, or the interface has been " +
+                    "called to early in SystemServer init");
+        }
     }
 
     /**