ANDROID: fips140: add service indicators

To satisfy the FIPS 140-3 "service indicators" requirement, add a
function which checks whether the given algorithm is "approved" or not.

Note that this function is a bit different from the module's other APIs
in that it is an exported symbol rather than a registration-based API.
This avoids needing to make kernel/KMI changes, so I think we should do
it this way if possible, given that it's unlikely this function will be
used in practice outside of the lab test.  Built-in code can still call
this function via symbol_get() if it really wants to.

Bug: 188620248
Change-Id: I26c976258fa9446b34eb189bba7154142d85da16
Signed-off-by: Eric Biggers <ebiggers@google.com>