Fix Android Studio warnings.

Type parameters can be ommited if defined and declared in same statement.
`onStart()` is deprecated and not required, as we target APIs > 5.
`Intent.FLAG_ACTIVITY_CLEAR_TASK` is not supported on APIs < 11 but we target 8.

app/src/main/java/org/fdroid/fdroid/installer/InstallManagerService.java

@@ -66,20 +66,20 @@ public class InstallManagerService extends Service {
      * matching the {@link App}s in {@code ACTIVE_APPS}. The key is the download URL, as
      * in {@link Apk#getUrl()} or {@code urlString}.
      */
-    private static final HashMap<String, Apk> ACTIVE_APKS = new HashMap<String, Apk>(3);
+    private static final HashMap<String, Apk> ACTIVE_APKS = new HashMap<>(3);
 
     /**
      * The collection of {@link App}s that are actively going through this whole process,
      * matching the {@link Apk}s in {@code ACTIVE_APKS}. The key is the
      * {@code packageName} of the app.
      */
-    private static final HashMap<String, App> ACTIVE_APPS = new HashMap<String, App>(3);
+    private static final HashMap<String, App> ACTIVE_APPS = new HashMap<>(3);
 
     /**
      * The array of active {@link BroadcastReceiver}s for each active APK. The key is the
      * download URL, as in {@link Apk#getUrl()} or {@code urlString}.
      */
-    private final HashMap<String, BroadcastReceiver[]> receivers = new HashMap<String, BroadcastReceiver[]>(3);
+    private final HashMap<String, BroadcastReceiver[]> receivers = new HashMap<>(3);
 
     /**
      * Get the app name based on a {@code urlString} key. The app name needs
@@ -91,7 +91,7 @@ public class InstallManagerService extends Service {
      * <p>
      * TODO <b>delete me once InstallerService exists</b>
      */
-    private static final HashMap<String, String> TEMP_HACK_APP_NAMES = new HashMap<String, String>(3);
+    private static final HashMap<String, String> TEMP_HACK_APP_NAMES = new HashMap<>(3);
 
     private LocalBroadcastManager localBroadcastManager;
     private NotificationManager notificationManager;

app/src/main/java/org/fdroid/fdroid/net/DownloaderService.java

@@ -30,6 +30,7 @@ import android.os.Looper;
 import android.os.Message;
 import android.os.PatternMatcher;
 import android.os.Process;
+import android.support.v4.content.IntentCompat;
 import android.support.v4.content.LocalBroadcastManager;
 import android.text.TextUtils;
 import android.util.Log;
@@ -109,14 +110,14 @@ public class DownloaderService extends Service {
     }
 
     @Override
-    public void onStart(Intent intent, int startId) {
+    public int onStartCommand(Intent intent, int flags, int startId) {
-        super.onStart(intent, startId);
         Utils.debugLog(TAG, "Received Intent for downloading: " + intent + " (with a startId of " + startId + ")");
         String uriString = intent.getDataString();
         if (uriString == null) {
             Log.e(TAG, "Received Intent with no URI: " + intent);
-            return;
+            return START_STICKY;
         }
+
         if (ACTION_CANCEL.equals(intent.getAction())) {
             Utils.debugLog(TAG, "Cancelling download of " + uriString);
             Integer whatToRemove = uriString.hashCode();
@@ -139,26 +140,21 @@ public class DownloaderService extends Service {
         } else {
             Log.e(TAG, "Received Intent with unknown action: " + intent);
         }
+
+        return START_REDELIVER_INTENT; // if killed before completion, retry Intent
     }
 
     public static PendingIntent getCancelPendingIntent(Context context, String urlString) {
         Intent cancelIntent = new Intent(context.getApplicationContext(), DownloaderService.class)
                 .setData(Uri.parse(urlString))
                 .setAction(ACTION_CANCEL)
-                .setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
+                .setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | IntentCompat.FLAG_ACTIVITY_CLEAR_TASK);
         return PendingIntent.getService(context.getApplicationContext(),
                 urlString.hashCode(),
                 cancelIntent,
                 PendingIntent.FLAG_UPDATE_CURRENT);
     }
 
-    @Override
-    public int onStartCommand(Intent intent, int flags, int startId) {
-        Utils.debugLog(TAG, "onStartCommand " + intent);
-        onStart(intent, startId);
-        return START_REDELIVER_INTENT; // if killed before completion, retry Intent
-    }
-
     @Override
     public void onDestroy() {
         Utils.debugLog(TAG, "Destroying downloader service. Will move to background and stop our Looper.");