Fixed some tests by using the application context.

Fixed some tests by using the application context.

Fixed some tests by using the application context.

Fixed some tests by using the application context.

src/androidTest/java/de/dennisguse/opentracks/ChartValueSeriesTest.java

@@ -15,8 +15,8 @@
  */
 package de.dennisguse.opentracks;
 
+import androidx.test.core.app.ApplicationProvider;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
-import androidx.test.platform.app.InstrumentationRegistry;
 
 import org.junit.Assert;
 import org.junit.Before;
@@ -35,7 +35,7 @@ public class ChartValueSeriesTest {
     @Before
     public void setUp() {
         series = new ChartValueSeries(
-                InstrumentationRegistry.getInstrumentation().getContext(),
+                ApplicationProvider.getApplicationContext(),
                 Integer.MIN_VALUE,
                 Integer.MAX_VALUE,
                 new int[]{100, 1000},