Fix test. getClearContent() return the decrypted content for encryp…

…ted Event, and it is null in this case

matrix-sdk-android/src/test/java/org/matrix/android/sdk/internal/session/event/ValidDecryptedEventTest.kt

@@ -89,7 +89,7 @@ class ValidDecryptedEventTest {
                 ).toContent()
         )
 
-        val unValidatedContent = mixedEvent.getClearContent().toModel<MessageTextContent>()
+        val unValidatedContent = mixedEvent.content.toModel<MessageTextContent>()
         unValidatedContent?.body shouldBe "some message"
 
         mixedEvent.toValidDecryptedEvent()?.clearContent?.toModel<MessageTextContent>() shouldBe null