Make "shared" filter more compatible with diff DBs

For the type BOOLEAN, in sqlalchemy,
it's mapped to BOOLEAN type if the backend database supports it,
otherwise, it's mapped to one of the Integer types, like SMALLINT,
and restrict the values to 1(True) and 0(False).

query_filter = (... | model.shared))
The above filter will generate a SQL where clause like:
where ... OR xxx.shared

This is not supported in databases which don't support BOOLEAN type.
Change it as below to make it more compatible:
query_filter = (... | model.shared == True))

It will generate a SQL where clause as below:
where ... OR xxx.shared = ?

In Python, True == 1, so this change is compatible
with both databases supporting BOOLEAN and those not supporting it.

Fix bug 1161195

Change-Id: Ic0ce0816d63b576a3469de0ed92cae4b19a3690e