Storage: SqlBlobStore no longer needs Lanugage object

Constructing a Language object in order to initialize the
BlobStoreFactory service causes a circular dependency
(see T231866).

SqlBlobStore was using the Language object to all iconv.
But nothing language specific is done in Language::iconv,
so we can just inline the call.

Bug: T231866
Change-Id: I90c25decbcff10ea762a2c7474a12fd2041b3abc