Incorrect color representation of Samsung J7 2017

Happens both over WiFi and USB.

Running commands from [#177](https://github.com/Genymobile/scrcpy/issues/177#issuecomment-397973971):

```bash
adb shell screenrecord /sdcard/test.mp4
adb pull /sdcard/test.mp4
```

results in correct video.

Broken commands:

```bash
scrcpy -b10K -m360
scrcpy -b2M -m600
scrcpy
adb shell screenrecord --output-format=h264 - | ffplay -
```

The video is ultra-smooth, but it looks as if everything below some level of luminosity is interpreted as gray:

Here is screenshot of Samsung Settings:

Here is screenshot of scrcpy:

Android 7.0 (stock, but installed custom kernel)
Samsung Experience 8.1
Kernel 3.18.14-Refined_Kernel-v2.8-Stable-J730F-G (custom kernel)
Model SM-J730F

Start by reproducing the issue with scrcpy and the adb/ffplay commands listed in the report on a Samsung SM-J730F running Android 7.0. Compare the displayed colors with the Android Settings screenshot and the adb screenrecord output. Done means scrcpy displays dark colors correctly without breaking the reported smooth video behavior.

Written by the indexing model from the issue text.