Q Upstream: Use ParcelFileDescriptor for storing large clip data.

This patch enables copy&paste-ing large data for Q and below.
Using content URI is the idiomatic way to transfer large data,
but none of the major editor apps (Docs, Evernote, Word, Gmail, etc.)
support content URI in clipboard as of today.
We will ask app developers to use content: URI and remove this function
in API 30 (R).

Bug: 111577843
Test: ClipboardManagerTest
Test: Manualy tested copying a large HTML text
Change-Id: If1798c5abcec691f4b17a45e583ed314b1c16ac2