Fix wrong unit type for contention count when parsing legacy Java profiles. (#404)

profile/legacy_java_profile.go

 				}
 			case "contention/resolution":
 				p.SampleType = []*ValueType{
-					{Type: "contentions", Unit: value},
+					{Type: "contentions", Unit: "count"},
 					{Type: "delay", Unit: value},
 				}
 			case "contention/sampling period":

profile/testdata/java.contention.string

 Period: 100
 Duration: 1h40
 Samples:
-contentions/microseconds delay/microseconds
+contentions/count delay/microseconds
         100        100: 1 2 
         100       1400: 3 4 5 6 7 8 9 10 11 12 13 14 15 16 10 17 18 19 20 21 22 23 24 25 26 27 28 29 
         200        200: 1 2