Install sqlite 3.50.4 source files

This installs sqlite 3.50.4 source files.  It does not include the new
version of sqlite in the build.  The actual version of sqlite that is
installed is controlled by a trunk-stable build flag, which is not
modified in this CL.

Flag: EXEMPT source install only
Bug: 430889718
Test: presubmit
Change-Id: Ic0617e6954caa960aca09f3863ffe60b6f53a194
11 files changed