PostgreSQL: Make l10n_cache.lc_value binary

Change-Id I427c6de5a0a29b43cff755db0eb8a750db620173 increases the
probability that a null byte will attempt to be stored in the
lc_value column.  PostgreSQL does not allow that byte in a text
column, so convert the column to bytea.

If the column already contains corrupted data, the upgrade routine
might fail.  To prevent this, delete the contents of the table before
changing the type.

Bug: 62098
Change-Id: Ie8368bde398b2ae4d3cfc9ee7bf35874bd2ded68
Merge "PostgreSQL: Make l10n_cache.lc_value binary"