fix a few more errorprone warnings

Author: jkwatson

exporters/common/src/test/java/io/opentelemetry/exporter/internal/metrics/ExporterInstrumentationTest.java

@@ -36,7 +36,7 @@ class ExporterInstrumentationTest {
   Supplier<MeterProvider> meterProviderSupplier = mock(Supplier.class);
 
   @ParameterizedTest
-  @EnumSource()
+  @EnumSource
   void validMeterProvider(InternalTelemetryVersion schemaVersion) {
     when(meterProviderSupplier.get())
         .thenReturn(
@@ -84,7 +84,7 @@ public AggregationTemporality getAggregationTemporality(
   }
 
   @ParameterizedTest
-  @EnumSource()
+  @EnumSource
   void noopMeterProvider(InternalTelemetryVersion schemaVersion) {
 
     when(meterProviderSupplier.get()).thenReturn(MeterProvider.noop());

sdk/metrics/src/test/java/io/opentelemetry/sdk/metrics/internal/data/MutableHistogramPointDataTest.java

@@ -103,7 +103,7 @@ void testSanity() {
     assertThat(anotherPointData.hashCode()).isNotEqualTo(pointData.hashCode());
   }
 
-  @Test()
+  @Test
   void testBoundaries() {
     MutableHistogramPointData pointData = new MutableHistogramPointData(10);
     assertThatThrownBy(