Add support for RtpEncodingParameters num_temporal_layers.

Configuring different number of temporal layers per simulcast layer is not supported.

Bug: webrtc:9785
Change-Id: I5709b2235233420e22e68fb0ae512305ae87e36c
Reviewed-on: https://webrtc-review.googlesource.com/c/102120
Commit-Queue: Åsa Persson <asapersson@webrtc.org>
Reviewed-by: Seth Hampson <shampson@webrtc.org>
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Reviewed-by: Rasmus Brandt <brandtr@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24942}

sdk/android/api/org/webrtc/RtpParameters.java

@@ -38,17 +38,20 @@ public class RtpParameters {
     @Nullable public Integer minBitrateBps;
     // The max framerate in fps for video.
     @Nullable public Integer maxFramerate;
+    // The number of temporal layers for video.
+    @Nullable public Integer numTemporalLayers;
     // SSRC to be used by this encoding.
     // Can't be changed between getParameters/setParameters.
     public Long ssrc;
 
     @CalledByNative("Encoding")
     Encoding(boolean active, Integer maxBitrateBps, Integer minBitrateBps, Integer maxFramerate,
-        Long ssrc) {
+        Integer numTemporalLayers, Long ssrc) {
       this.active = active;
       this.maxBitrateBps = maxBitrateBps;
       this.minBitrateBps = minBitrateBps;
       this.maxFramerate = maxFramerate;
+      this.numTemporalLayers = numTemporalLayers;
       this.ssrc = ssrc;
     }
 
@@ -75,6 +78,12 @@ public class RtpParameters {
       return maxFramerate;
     }
 
+    @Nullable
+    @CalledByNative("Encoding")
+    Integer getNumTemporalLayers() {
+      return numTemporalLayers;
+    }
+
     @CalledByNative("Encoding")
     Long getSsrc() {
       return ssrc;