Merge branch 'hotfix/danger_on-is-true-for-assets-provider' into develop
Renamed certificate handling methods.

I still let one method to bypass hostname verifier, otherwise dev.bm
will not work.

I've reduced downloading functions to 3: download without CA, download
with commercial CA and download with provider CA.

I only download CA cert once, when the user selects the corresponding
provider. Each time a user switch provider, the cert is downloaded
(along with other json files).
Removed cookie to logout chain.
Commented all manual cookie management.

I send session_id cookie in the request for 1/cert, getting it from
LeapHttpClient directly.
Apache HTTP to Android HttpsURLConnection started.

SRP parameter A tries to be sent via HttpsURLConnection. Right now, we
have a problem with certificates because I'm not using provider CA cert
to get the response. I'm going to merge the branch with better method
names to download response using already existing code.
Replaced Apache HTTP client with HttpURLConnection

I do not manually manage cookies anymore, letting HttpURLConnection
manage them via default CookieHandler (using
CookiePolicy.ACCEPT_ORIGINAL_SERVER).
Merge branch 'bug/inconsistent-cookie-management' into develop
Moved result constants to ProviderAPI.
Moved all constants from ConfigHelper.

They have been relocated to the corresponding classes.
Erroneous CA cert download correctly handled.

If there is an error while downloading CA cert on downloadJsonFiles, false is returned and progress dialog is dismissed.