install viper driver during module install

this installs the viper driver at module install time,
removing the need to install the driver using the viper app.
The viper binaries have been extracted from the viper apk.
The patching audio_effects.conf script has been copied from the ViPER4AndroidFX-Legacy Module:
https://github.com/Magisk-Modules-Repo/ViPER4AndroidFX-Legacy/blob/9241c9801e33505a1cc63b60c7e7f281c97dfc15/common/unity_install.sh#L249
The patching process hasn't changed since then, there is no reason not to continue patching this way.

Author: programminghoch10

magiskmodule/common/install.sh

@@ -240,18 +240,35 @@ cp -f $MODPATH/v4afx.apk $FOL/v4afx.apk
 umount -l $(mount | awk '{print $3}' | grep 'libv4a_fx.so')
 killall audioserver
 
+
+ui_print " "
+ui_print "- Patching audio_effects.xml"
+mkdir -p $MODPATH/system/vendor/etc
+AUDIO_EFFECTS_FILE=$MODPATH/system/vendor/etc/audio_effects.xml
+cp -f /vendor/etc/audio_effects.xml $AUDIO_EFFECTS_FILE
+sed -i "/v4a_standard_fx/d" $AUDIO_EFFECTS_FILE
+sed -i "/v4a_fx/d" $AUDIO_EFFECTS_FILE
+sed -i "/<libraries>/ a\        <library name=\"v4a_fx\" path=\"libv4a_fx.so\"\/>" $AUDIO_EFFECTS_FILE
+sed -i "/<effects>/ a\        <effect name=\"v4a_standard_fx\" library=\"v4a_fx\" uuid=\"41d3c987-e6cf-11e3-a88a-11aba5d5c51b\"\/>" $AUDIO_EFFECTS_FILE
+
+# here is how to strace v4a app:
+#  run adb root
+#  run in adb shell
+#    while [ -z "$(pidof com.pittvandewitt.viperfx)" ]; do true; done && (strace -f -p $(pidof com.pittvandewitt.viperfx) 2>&1| grep -i "open")
+ui_print " "
 ui_print "- Installing ViPER4AndroidFX $(grep_prop version $MODPATH/module.prop)..."
+ui_print "   After this completes,"
+#ui_print "   open V4A app and follow the prompts"
+ui_print "   you MUST REBOOT before opening the app"
+#ui_print "   reboot your device."
+ui_print " "
 $ENFORCE && setenforce 0
 (pm install $MODPATH/v4afx.apk >/dev/null 2>&1) || abort "Failed to install V4AFX!"
 $ENFORCE && setenforce 1
 
 # Install temporary service script
 install_script -l $MODPATH/common/service.sh
 
-ui_print "   After this completes,"
-ui_print "   open V4A app and follow the prompts"
-ui_print " "
-sleep 5
 
 REMS=$(find $NVBASE/modules/*/system $MODULEROOT/*/system -type f -name "ViPER4AndroidFX.apk" 2>/dev/null)
 if [ "$REMS" ]; then