Remove remaining variables related to incomplete frames.

Bug: webrtc:9378, webrtc:7408
Change-Id: I5b26f09a2da13906b421d0bcf615e721b66d4ce7
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/190860
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Commit-Queue: Philip Eliasson <philipel@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32552}

sdk/android/tests/src/org/webrtc/AndroidVideoDecoderTest.java

@@ -187,7 +187,6 @@ public class AndroidVideoDecoderTest {
     return EncodedImage.builder()
         .setBuffer(ByteBuffer.wrap(ENCODED_TEST_DATA), null)
         .setFrameType(FrameType.VideoFrameKey)
-        .setCompleteFrame(true)
         .createEncodedImage();
   }