Adapt to google::protobuf::int64 type change

Protobuf 3.9.1 redefines google::protobuf::int64 from long long to
int64_t, which is sometimes long and sometimes long long.  Use PRId64
to print it.

Bug: 117607748
Test: m checkbuild
Exempt-From-Owner-Approval: approved at https://android-review.googlesource.com/q/I6699cfdb0f0424aa3e1c98b59d941beb9f133055
Change-Id: I6699cfdb0f0424aa3e1c98b59d941beb9f133055
1 file changed