fix #1139 CI build

- fix NPEs in TrackPointCreator.fill()
- fix locale dependant tests
- wait for UI components
- extract utility functions into EspressoUtils

src/androidTest/java/de/dennisguse/opentracks/services/announcement/VoiceAnnouncementUtilsTest.java

@@ -9,11 +9,14 @@ import androidx.test.core.app.ApplicationProvider;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 
 import org.junit.Before;
+import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
 import java.time.Duration;
+import java.util.Locale;
 
+import de.dennisguse.opentracks.LocaleRule;
 import de.dennisguse.opentracks.content.data.TestDataUtil;
 import de.dennisguse.opentracks.data.ContentProviderUtils;
 import de.dennisguse.opentracks.data.TrackPointIterator;
@@ -29,6 +32,9 @@ import de.dennisguse.opentracks.ui.intervals.IntervalStatistics;
 @RunWith(AndroidJUnit4.class)
 public class VoiceAnnouncementUtilsTest {
 
+    @Rule
+    public final LocaleRule mLocaleRule = new LocaleRule(Locale.ENGLISH);
+
     private final Context context = ApplicationProvider.getApplicationContext();
     private ContentProviderUtils contentProviderUtils;