Revert of Add ability to scale to arbitrary factors (patchset #7 id:120001 of https://codereview.webrtc.org/2555483005/ )

Reason for revert:
Issue discovered with scaling back up.

Original issue's description:
> Add ability to scale to arbitrary factors
>
> This CL adds a fallback for the case when no optimized scale factor produces a low enough resolution for what was requested. It also ensures that all resolutions provided by the video adapter are divisible by four. This is required by some hardware implementations.
>
> BUG=webrtc:6837
>
> Committed: https://crrev.com/710c335d785b104bda4a912bd7909e4d27f9b04f
> Cr-Commit-Position: refs/heads/master@{#15469}

TBR=magjed@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:6837

Review-Url: https://codereview.webrtc.org/2557323002
Cr-Commit-Position: refs/heads/master@{#15470}

webrtc/sdk/android/src/jni/androidvideotracksource.cc

@@ -12,19 +12,13 @@
 
 #include <utility>
 
-namespace {
-// MediaCodec wants resolution to be divisible by 2.
-const int kRequiredResolutionAlignment = 2;
-}
-
 namespace webrtc {
 
 AndroidVideoTrackSource::AndroidVideoTrackSource(rtc::Thread* signaling_thread,
                                                  JNIEnv* jni,
                                                  jobject j_egl_context,
                                                  bool is_screencast)
-    : AdaptedVideoTrackSource(kRequiredResolutionAlignment),
-      signaling_thread_(signaling_thread),
+    : signaling_thread_(signaling_thread),
       surface_texture_helper_(webrtc_jni::SurfaceTextureHelper::create(
           jni,
           "Camera SurfaceTextureHelper",