Android: Remove gradle.properties file handling

The modification of gradle.properties files was originally a feature of
the Android plugin which eventually moved over to androiddeployqt.

Moreover, this code got accidentally disabled in Qt Creator 4.10 and was
appartently not missed till now. I only noticed it while "FilePath-
ifying" code in the Andsroid plugin.

This change removes the gradle.properties file handling code from Qt
Creator.

Fixes: QTCREATORBUG-28494
Change-Id: Id4f2722f4965c877a065386b34a71d8368147b08
Reviewed-by: Assam Boudjelthia <assam.boudjelthia@qt.io>

src/plugins/android/createandroidmanifestwizard.cpp

@@ -293,11 +293,8 @@ void CreateAndroidManifestWizard::createAndroidTemplateFiles()
             QTC_ASSERT(gradlePath.exists(), return);
             FileUtils::copyRecursively(gradlePath, m_directory, nullptr, copy);
         }
-
-        AndroidManager::updateGradleProperties(target, m_buildKey);
     }
 
-
     QString androidPackageDir;
     ProjectNode *node = target->project()->findNodeForBuildKey(m_buildKey);
     if (node) {