rename variables to prevent override by os

.env.example

@@ -10,8 +10,8 @@
 
 ### User ID:
 # This is used to set the correct permissions for the accessing the audio device and accessing the PulseAudio socket
-USER_ID="1000"
-USER_GROUP="1000"
+LVA_USER_ID="1000"
+LVA_USER_GROUP="1000"
 
 ### Name for the client (optional):
 # by default it uses the HOSTNAME variable from the piCompose environment which includes the MAC from the network card
@@ -20,8 +20,8 @@ USER_GROUP="1000"
 ### PulseAudio socket path on the host:
 # PulseAudio Server:    /run/user/1000/pulse
 # Pipewire Server:      /run/user/1000/pulse/native
-PULSE_SERVER="unix:/run/user/${USER_ID}/pulse/native"
-XDG_RUNTIME_DIR="/run/user/${USER_ID}"
+LVA_PULSE_SERVER="unix:/run/user/${LVA_USER_ID}/pulse/native"
+LVA_XDG_RUNTIME_DIR="/run/user/${LVA_USER_ID}"
 
 ### Path to the preferences file (optional):
 # PREFERENCES_FILE="/app/configuration/preferences.json"