SF: DisplayCommand.colorTransform is just a matrix

Remove the hint from DisplayCommand.colorTransform as currently
we only use ColorTransform::IDENTITY and ColorTransform::ARBITRARY_MATRIX,
which both can be expressed using a matrix.

Bug: 208879711
Test: VTS
Change-Id: I1c335647aabb7f89c2c89e54abfc839d10a659fb
diff --git a/services/surfaceflinger/DisplayHardware/ComposerHal.h b/services/surfaceflinger/DisplayHardware/ComposerHal.h
index 84e227d..a6a1e6f 100644
--- a/services/surfaceflinger/DisplayHardware/ComposerHal.h
+++ b/services/surfaceflinger/DisplayHardware/ComposerHal.h
@@ -139,7 +139,7 @@
                                   int acquireFence, Dataspace dataspace,
                                   const std::vector<IComposerClient::Rect>& damage) = 0;
     virtual Error setColorMode(Display display, ColorMode mode, RenderIntent renderIntent) = 0;
-    virtual Error setColorTransform(Display display, const float* matrix, ColorTransform hint) = 0;
+    virtual Error setColorTransform(Display display, const float* matrix) = 0;
     virtual Error setOutputBuffer(Display display, const native_handle_t* buffer,
                                   int releaseFence) = 0;
     virtual Error setPowerMode(Display display, IComposerClient::PowerMode mode) = 0;