close streams more consistently (outside of encrypt/decrypt), force a new output filename guess if the ASCII armour checkbox state changes

src/org/thialfihar/android/apg/DecryptFileActivity.java

@@ -186,6 +186,8 @@ public class DecryptFileActivity extends BaseActivity {
             OutputStream out = new FileOutputStream(mOutputFilename);
 
             data = Apg.decrypt(in, out, Apg.getPassPhrase(), this, mAssumeSymmetricEncryption);
+
+            out.close();
         } catch (PGPException e) {
             error = e.getMessage();
         } catch (IOException e) {