Rename cancelDownload() to deleteUpdate()

The method can be used to delete any update, incomplete or not.

src/org/lineageos/updater/UpdatesListAdapter.java

@@ -350,7 +350,7 @@ public class UpdatesListAdapter extends RecyclerView.Adapter<UpdatesListAdapter.
                         new DialogInterface.OnClickListener() {
                             @Override
                             public void onClick(DialogInterface dialog, int which) {
-                                mUpdaterController.cancelDownload(downloadId);
+                                mUpdaterController.deleteUpdate(downloadId);
                             }
                         })
                 .setNegativeButton(android.R.string.cancel, null);

src/org/lineageos/updater/controller/Controller.java

@@ -38,7 +38,7 @@ public interface Controller {
 
     boolean pauseDownload(String downloadId);
 
-    boolean cancelDownload(String downloadId);
+    boolean deleteUpdate(String downloadId);
 
     boolean resumeDownload(String downloadId);
 

src/org/lineageos/updater/controller/UpdaterController.java

@@ -446,7 +446,7 @@ public class UpdaterController implements Controller {
     }
 
     @Override
-    public boolean cancelDownload(String downloadId) {
+    public boolean deleteUpdate(String downloadId) {
         Log.d(TAG, "Cancelling " + downloadId);
         if (!mDownloads.containsKey(downloadId) || isDownloading(downloadId)) {
             return false;