it was both WW II and Ghandiji are responsible for freedom because it was bapuji's idea to call quit india in 1942 as he knew britishers will not give freedom once the war was over. and he knew when to do it. so he struck when iron was hot. that led to the downfall of the britishers not the war itself. then how come we got freedom after gandhi came not before. so credit goes to him also. because of his way only we got freedom. and one thing more there were strikes around the country during the war and none of indian soldiers fought the war. even the britishers knew when the country is united they cannot rule us. even britishers know we got independence because of gandhi. so the history rightly written as it says because of WW II and gandhiji's efforts we got freedom. not solely because WW II.
