Move isElementCallAvailable fun to new SessionEnterpriseService, which implementations can get the current MatrixClient.

libraries/matrix/test/src/main/kotlin/io/element/android/libraries/matrix/test/FakeMatrixClient.kt

@@ -89,6 +89,7 @@ class FakeMatrixClient(
     private val ignoreUserResult: (UserId) -> Result<Unit> = { lambdaError() },
     private var unIgnoreUserResult: (UserId) -> Result<Unit> = { Result.success(Unit) },
     private val canReportRoomLambda: () -> Boolean = { false },
+    private val isLivekitRtcSupportedLambda: () -> Boolean = { false },
     override val ignoredUsersFlow: StateFlow<ImmutableList<UserId>> = MutableStateFlow(persistentListOf()),
 ) : MatrixClient {
     var setDisplayNameCalled: Boolean = false
@@ -334,4 +335,8 @@ class FakeMatrixClient(
     override suspend fun canReportRoom(): Boolean {
         return canReportRoomLambda()
     }
+
+    override suspend fun isLivekitRtcSupported(): Boolean {
+        return isLivekitRtcSupportedLambda()
+    }
 }