ISPs: prefer confederation ASNs

[progwriter]

Since ISPs are external to any network, prefer confederation remote ASes over the peer's local AS.

[batfish-bot]

This change is 

[codecov]

Codecov Report

Merging #4956 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@             Coverage Diff              @@
##             master    #4956      +/-   ##
============================================
+ Coverage     76.55%   76.55%   +<.01%     
- Complexity    29823    29826       +3     
============================================
  Files          2384     2384              
  Lines        115025   115027       +2     
  Branches      13592    13592              
============================================
+ Hits          88056    88064       +8     
+ Misses        20299    20290       -9     
- Partials       6670     6673       +3

Impacted Files	Coverage Δ	Complexity Δ
...java/org/batfish/common/util/IspModelingUtils.java	92.65% <100%> (+0.05%)	35 <0> (ø)	⬇️
...rg/batfish/dataplane/ibdp/EigrpRoutingProcess.java	93.12% <0%> (-0.39%)	69% <0%> (-1%)
...col/src/main/java/org/batfish/role/InferRoles.java	90.15% <0%> (-0.38%)	63% <0%> (-1%)
...tfish/representation/cisco/CiscoConfiguration.java	84.12% <0%> (+0.12%)	510% <0%> (+1%)	⬆️
...main/java/org/batfish/datamodel/BgpPeerConfig.java	91.8% <0%> (+1.63%)	40% <0%> (ø)	⬇️
...org/batfish/datamodel/flow/BidirectionalTrace.java	81.81% <0%> (+2.27%)	14% <0%> (+1%)	⬆️
...rc/main/java/org/batfish/datamodel/flow/Trace.java	90.32% <0%> (+3.22%)	13% <0%> (+2%)	⬆️
.../src/main/java/org/batfish/datamodel/flow/Hop.java	60% <0%> (+6.66%)	6% <0%> (+1%)	⬆️

[haverma]

Reviewed 2 of 2 files at r1.
Reviewable status: complete! all files reviewed, all discussions resolved