cmsdk: Allow services to conditionally start before decryption

* Essentially everything in CMSDK should remain silent when we
   are being prompted to enter a passcode for decrypting the
   device. Unfortunately, simply shutting off CMSDK entirely
   will cause crashes everywhere. We need to be somewhat
   selective about it.
 * Motivation for this was LiveDisplay kicking into night mode before
   decrypted due to location services failing.

Change-Id: I4d745debb2894776258343e8696ce5144f094404

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

@@ -17,6 +17,7 @@
 package org.cyanogenmod.platform.internal;
 
 import android.content.Context;
+import android.os.SystemProperties;
 import android.util.Slog;
 import com.android.server.LocalServices;
 import com.android.server.SystemServiceManager;
@@ -33,11 +34,21 @@ public class CMSystemServer {
     private Context mSystemContext;
     private CMSystemServiceHelper mSystemServiceHelper;
 
+    private static final String ENCRYPTING_STATE = "trigger_restart_min_framework";
+    private static final String ENCRYPTED_STATE = "1";
+
     public CMSystemServer(Context systemContext) {
         mSystemContext = systemContext;
         mSystemServiceHelper = new CMSystemServiceHelper(mSystemContext);
     }
 
+    public static boolean coreAppsOnly() {
+        // Only run "core" apps+services if we're encrypting the device.
+        final String cryptState = SystemProperties.get("vold.decrypt");
+        return ENCRYPTING_STATE.equals(cryptState) ||
+               ENCRYPTED_STATE.equals(cryptState);
+    }
+
     /**
      * Invoked via reflection by the SystemServer
      */
@@ -64,8 +75,13 @@ public class CMSystemServer {
                 CMSystemService cmSystemService =  mSystemServiceHelper.getServiceFor(service);
                 if (context.getPackageManager().hasSystemFeature(
                         cmSystemService.getFeatureDeclaration())) {
-                    Slog.i(TAG, "Starting service " + service);
-                    ssm.startService(cmSystemService.getClass());
+                    if (coreAppsOnly() && !cmSystemService.isCoreService()) {
+                        Slog.d(TAG, "Not starting " + service +
+                                " - only parsing core apps");
+                    } else {
+                        Slog.i(TAG, "Starting service " + service);
+                        ssm.startService(cmSystemService.getClass());
+                    }
                 } else {
                     Slog.i(TAG, "Not starting service " + service +
                             " due to feature not declared on device");

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

@@ -25,4 +25,13 @@ public abstract class CMSystemService extends SystemService {
     }
 
     public abstract String getFeatureDeclaration();
+
+
+    /**
+     * Override and return true if the service should be started
+     * before the device is decrypted.
+     */
+    public boolean isCoreService() {
+        return true;
+    }
 }

cm/lib/main/java/org/cyanogenmod/platform/internal/display/LiveDisplayService.java

@@ -150,6 +150,11 @@ public class LiveDisplayService extends CMSystemService {
         return CMContextConstants.Features.LIVEDISPLAY;
     }
 
+    @Override
+    public boolean isCoreService() {
+        return false;
+    }
+
     @Override
     public void onStart() {
         publishBinderService(CMContextConstants.CM_LIVEDISPLAY_SERVICE, mBinder);