Change callstack ids to uint64_t.
Change callstack ids to uint64_t.

They were accidentally left over as uint32_t.

Change-Id: Ia26c275d9e210928c7cb88671c567aa43776aae8
google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto