If sdk not started, let's not add embrace in the middle of requests

[cesarmax22]

Goal

if embrace is not started then create a default UrlStreamHandler, otherwise create an EmbraceUrlStreamHandler

Testing

Release Notes

WHAT:

WHY:

WHO:

[codecov]

Codecov Report

Attention: Patch coverage is 66.66667% with 3 lines in your changes are missing coverage. Please review.

Project coverage is 80.55%. Comparing base (0b112a9) to head (ddc59c9).
Report is 11 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #740      +/-   ##
==========================================
- Coverage   80.74%   80.55%   -0.19%     
==========================================
  Files         423      423              
  Lines       11132    11152      +20     
  Branches     1672     1673       +1     
==========================================
- Hits         8989     8984       -5     
- Misses       1439     1460      +21     
- Partials      704      708       +4     

Files	Coverage Δ
...l/network/http/EmbraceUrlStreamHandlerFactory.java	45.00% <66.66%> (+5.00%)	⬆️

... and 21 files with indirect coverage changes

[bidetofevil]

As discussed, this happens at class loading time, so once it's set, it's permanent, so we can't really do that