Allow web-based video call

Issue

Two-way video calls don't work on POCO X3/X3 NFC.
Tested by @FFast :

• Telegram
  • https://t.me/ut_pocox3/11603
  • https://t.me/ut_pocox3/11634
  • https://t.me/ut_pocox3/11640
• Jitsi
  • https://t.me/ut_pocox3/11641
• Whereby
  • https://t.me/ut_pocox3/11685

Also, several WebRTC tests at https://webrtc.github.io/test-pages/ and https://webrtc.github.io/samples/ do not work and crash Morph Browser.
For example

• https://webrtc.github.io/test-pages/src/peer2peer-video/
• https://webrtc.github.io/samples/src/content/peerconnection/upgrade/

Fix

Chromium version used in QtWebengine 5 does not support WebRTC hardware decoding.
Thus, adding --disable-webrtc-hw-decoding to QTWEBENGINE_CHROMIUM_FLAGS solves the issue.
I did it in the existing overlayed /etc/profile.d/devicehacks.sh script.
But since it should be run after /etc/profile.d/qtwebengine-gpu.sh, I renamed it to increase its priority.

Tests

I built the images and flashed them on my phone with fastboot flash.

Now WebRTC tests at https://webrtc.github.io/test-pages/ and https://webrtc.github.io/samples/ work fine and don't crash Morph Browser anymore.

@FFast has tested successfully the --disable-webrtc-hw-decoding flag with Whereby and Jitsi