Apply suggestions from code review

Co-authored-by: Nikita Ogorodnikov <[email protected]>

Author: fuzzybinary

features/dd-sdk-android-rum/src/main/kotlin/com/datadog/android/rum/internal/RumFeature.kt

@@ -387,6 +387,7 @@ internal class RumFeature(
      */
     internal fun enableJankStatsTracking(activity: Activity) {
         try {
+            @Suppress("UnsafeThirdPartyFunctionCall")
             jankStatsActivityLifecycleListener?.onActivityStarted(activity)
         } catch (@Suppress("TooGenericExceptionCaught") e: Exception) {
             sdkCore.internalLogger.log(

features/dd-sdk-android-rum/src/main/kotlin/com/datadog/android/rum/internal/monitor/DatadogRumMonitor.kt

@@ -646,13 +646,9 @@ internal class DatadogRumMonitor(
     }
 
     override fun enableJankStatsTracking(activity: Activity) {
-        val rumFeatureScope = sdkCore.getFeature(Feature.RUM_FEATURE_NAME)
+        sdkCore.getFeature(Feature.RUM_FEATURE_NAME)
             ?.unwrap<RumFeature>()
-        if (rumFeatureScope == null) {
-            return
-        }
-
-        rumFeatureScope.enableJankStatsTracking(activity)
+            ?.enableJankStatsTracking(activity)
     }
 
     // endregion

features/dd-sdk-android-rum/src/test/kotlin/com/datadog/android/rum/internal/RumFeatureTest.kt

@@ -545,13 +545,14 @@ internal class RumFeatureTest {
             fakeConfiguration,
             lateCrashReporterFactory = { mockLateCrashReporter }
         )
-        testedFeature.jankStatsActivityLifecycleListener = mock()
+        val mockJankStatsActivityLifecycleListener = mock<JankStatsActivityLifecycleListener>()
+        testedFeature.jankStatsActivityLifecycleListener = mockJankStatsActivityLifecycleListener
 
         // When
         testedFeature.enableJankStatsTracking(activity)
 
         // Then
-        verify(testedFeature.jankStatsActivityLifecycleListener)!!.onActivityStarted(activity)
+        verify(mockJankStatsActivityLifecycleListener).onActivityStarted(activity)
     }
 
     @Test

features/dd-sdk-android-rum/src/test/kotlin/com/datadog/android/rum/internal/vitals/JankStatsActivityLifecycleListenerTest.kt

@@ -134,7 +134,7 @@ internal class JankStatsActivityLifecycleListenerTest {
         testedJankListener.onActivityStarted(mockActivity)
 
         // Then
-        assertThat(testedJankListener.activeActivities[mockWindow]?.size).isEqualTo(1)
+        assertThat(testedJankListener.activeActivities[mockWindow]).hasSize(1)
     }
 
     @Test