setup_testapp_service: switch to ndk 19c

Author: zworkb

testapps/setup_testapp_service.py

@@ -8,7 +8,7 @@
                    'android-api': 27,
                    'ndk-api': 21,
                    'sdk-dir':'/opt/android/android-sdk/',
-                   'ndk-dir':'/opt/android/android-ndk-r17c/',
+                   'ndk-dir':'/opt/android/android-ndk-r19c/',
                    'dist-name': 'testapp_service',
                    'ndk-version': '10.3.2',
                    'bootstrap': 'service_only',