PAN: fix up default BGP AF capabilities

[progwriter]

AllowRemoteAsOut is true; Warn in the case where we do not support correct enable-sender-side-loop-detection semantics.

[batfish-bot]

This change is 

[corinaminer]

Reviewed 7 of 7 files at r1.
Reviewable status: complete! all files reviewed, all discussions resolved

[codecov]

Codecov Report

Merging #6563 (bed9808) into master (c6b54d7) will decrease coverage by 0.01%.
The diff coverage is 83.33%.

@@             Coverage Diff              @@
##             master    #6563      +/-   ##
============================================
- Coverage     73.39%   73.38%   -0.02%     
- Complexity    35709    35710       +1     
============================================
  Files          2837     2837              
  Lines        144134   144152      +18     
  Branches      17427    17430       +3     
============================================
- Hits         105792   105787       -5     
- Misses        29960    29976      +16     
- Partials       8382     8389       +7     

Impacted Files	Coverage Δ	Complexity Δ
...epresentation/palo_alto/PaloAltoConfiguration.java	88.88% <71.42%> (-0.11%)	398.00 <0.00> (ø)
...rammar/palo_alto/PaloAltoConfigurationBuilder.java	87.63% <100.00%> (+0.01%)	471.00 <1.00> (+1.00)
.../org/batfish/representation/palo_alto/BgpPeer.java	100.00% <100.00%> (ø)	19.00 <2.00> (+2.00)
.../datamodel/routing_policy/statement/Statement.java	72.72% <0.00%> (-9.10%)	6.00% <0.00%> (-1.00%)
...rg/batfish/identifiers/StorageBasedIdResolver.java	85.29% <0.00%> (-5.89%)	22.00% <0.00%> (ø%)
.../org/batfish/dataplane/rib/RouteAdvertisement.java	83.67% <0.00%> (-4.09%)	18.00% <0.00%> (-1.00%)
...col/src/main/java/org/batfish/role/InferRoles.java	89.54% <0.00%> (-1.37%)	50.00% <0.00%> (-1.00%)
...src/main/java/org/batfish/coordinator/PoolMgr.java	59.52% <0.00%> (-1.20%)	15.00% <0.00%> (-1.00%)
...ain/java/org/batfish/storage/FileBasedStorage.java	86.19% <0.00%> (-0.55%)	249.00% <0.00%> (ø%)
...java/org/batfish/dataplane/ibdp/VirtualRouter.java	90.58% <0.00%> (-0.32%)	206.00% <0.00%> (-1.00%)
... and 4 more