Assert Parcel not in pool when used (partial reland^2)

This reverts commit 98636f80.

Use in a single function now that should not be inlined
so much, as adding to writeInt caused too much
frameworks.jar increase.

This costs only 0.026% of frameworks.jar
(8979000 -> 8981400)

Test: boot
Bug: 381155347
Change-Id: I84c9079090ec89a269be177d8679ed326776ab38