Init max supported H.264 profile at runtime on iOS

Bug: webrtc:9134, webrtc:7992
Change-Id: Id24c570bf3296298901f61ee817a3d7c3f8c6347
Reviewed-on: https://webrtc-review.googlesource.com/71560
Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
Commit-Queue: Kári Helgason <kthelgason@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23034}

sdk/objc/Framework/Classes/PeerConnection/RTCDefaultVideoEncoderFactory.m

@@ -25,7 +25,7 @@
 
 + (NSArray<RTCVideoCodecInfo *> *)supportedCodecs {
   NSDictionary<NSString *, NSString *> *constrainedHighParams = @{
-    @"profile-level-id" : kRTCLevel31ConstrainedHigh,
+    @"profile-level-id" : kRTCMaxSupportedH264ProfileLevelConstrainedHigh,
     @"level-asymmetry-allowed" : @"1",
     @"packetization-mode" : @"1",
   };
@@ -34,7 +34,7 @@
                                    parameters:constrainedHighParams];
 
   NSDictionary<NSString *, NSString *> *constrainedBaselineParams = @{
-    @"profile-level-id" : kRTCLevel31ConstrainedBaseline,
+    @"profile-level-id" : kRTCMaxSupportedH264ProfileLevelConstrainedBaseline,
     @"level-asymmetry-allowed" : @"1",
     @"packetization-mode" : @"1",
   };