Use SparseArray instead of HashMap in vCard code

TESTED:
- prepare three vCard files: large.vcf, middle.vcf, and small.vcf
- import them orderly
- cancel middle.vcf during importing large.vcf
- after finishing everything, check
-- the service finishes
-- only large.vcf and small.vcf are imported

Bug: 6013599
Change-Id: I00c3fc1ee804001ccc937ea13a5755daca938f89