Re-enable string metric tests

glean-core/android/src/test/java/mozilla/telemetry/glean/private/StringMetricTypeTest.kt

@@ -17,7 +17,6 @@ import org.junit.Assert.assertEquals
 import org.junit.Assert.assertFalse
 import org.junit.Assert.assertTrue
 import org.junit.Before
-import org.junit.Ignore
 import org.junit.Test
 import org.junit.runner.RunWith
 import org.robolectric.RobolectricTestRunner
@@ -33,7 +32,6 @@ class StringMetricTypeTest {
         resetGlean()
     }
 
-    @Ignore("Ignoring the test as the testing API for strings is not implemented")
     @Test
     fun `The API saves to its storage engine`() {
         // Define a 'stringMetric' string metric, which will be stored in "store1"
@@ -58,7 +56,6 @@ class StringMetricTypeTest {
         assertEquals("overriddenValue", stringMetric.testGetValue())
     }
 
-    @Ignore("Ignoring the test as the testing API for strings is not implemented")
     @Test
     fun `strings with no lifetime must not record data`() {
         // Define a 'stringMetric' string metric, which will be stored in
@@ -78,7 +75,6 @@ class StringMetricTypeTest {
             stringMetric.testHasValue())
     }
 
-    @Ignore("Ignoring the test as the testing API for strings is not implemented")
     @Test
     fun `disabled strings must not record data`() {
         // Define a 'stringMetric' string metric, which will be stored in "store1". It's disabled
@@ -98,7 +94,6 @@ class StringMetricTypeTest {
             stringMetric.testHasValue())
     }
 
-    @Ignore("Ignoring the test as the testing API for strings is not implemented")
     @Test(expected = NullPointerException::class)
     fun `testGetValue() throws NullPointerException if nothing is stored`() {
         val stringMetric = StringMetricType(
@@ -111,7 +106,6 @@ class StringMetricTypeTest {
         stringMetric.testGetValue()
     }
 
-    @Ignore("Ignoring the test as the testing API for strings is not implemented")
     @Test
     fun `The API saves to secondary pings`() {
         // Define a 'stringMetric' string metric, which will be stored in "store1" and "store2"