Update sqlite cflags

Always set HAVE_POSIX_FALLOCATE=1, it is present on all supported
platforms (glibc, musl and bionic).

Set SQLITE_ENABLE_DBSTAT_VTAB=1 and SQLITE_ENABLE_ICU=1, etc. instead
of just defining SQLITE_ENABLE_DBSTAT_VTAB and SQLITE_ENABLE_ICU.
sqlite uses a mixture of #if and #if defined on most of the configuration
variables, and defining them without setting them to atrue value is
treating them as partially enabled.

Bug: 223257095
Test: atest SQLiteSecurityTest
Change-Id: Ibf648e7cedf27912dc4b025eebcb8c02a3daf1cd