“Squatting” implies that the knees aren’t on the ground;
“sitting back on the haunches” can be used in the same sense as “squatting” (see here and here).
“hunkering” can mean squatting too, but often implies that one leg is extended slightly forward so that the foot rests flat on the ground, like this;
“kneeling” covers any sitting posture in which the knees are on the floor and the legs are parallel. So we’re talking about a form of kneeling here, but one in which the buttocks are resting on the feet. As @ekans says, this is what the Japanese call seiza. We don’t have an English term for this specific posture, so seiza is sometimes translated as “kneeling sitting”, as here.