Ok, so whitout bridges :
"updating settings in Tor services
Updating torrc custom configuration
Orbot is starting
Connected to Tor control port
Added control port event handler"
And with bridges :
"updating settings in Tor services
Updating torrc custom configuration
Orbot is starting
connected to tor control port
Added control port event handler
WARN: problem bootstrapping. Stuck at 1%
Connecting to pluggable transport (Connection refused;)
WARN : 2 connections have failed
WARNED : 2 connections died in state connect()ing with SSL state (No SSL object).
In both cases, it just load indefinitely.