browser-support needs to be an implicit interface, not implicit classic

[Pat McGowan]

While running any browser/webapp on the arm64 dragonboard, they would not run under strict confinement.

Per jdstrand we need browser-support as an implicit interface, not just implicit classic.

Other denials to udev and attr/current

Feb 23 21:07:47 patsdragon audit[4036]: AVC apparmor="DENIED" operation="open" profile="snap.testdemo.testdemo" name="/run/udev/data/+platform:1a00000.qcom,mdss_mdp" pid=4036 comm="webapp-containe" requested_mask="r" denied_mask="r" fsuid=1000 ouid=0
Feb 23 21:07:47 patsdragon kernel: audit: type=1400 audit(1487884067.942:3248): apparmor="DENIED" operation="open" profile="snap.testdemo.testdemo" name="/run/udev/data/+platform:1a00000.qcom,mdss_mdp" pid=4036 comm="webapp-containe" requested_mask="r" denied_mask="r" fsuid=1000 ouid=0

Feb 23 21:07:48 patsdragon audit[4036]: AVC apparmor="DENIED" operation="open" profile="snap.testdemo.testdemo" name="/proc/4036/attr/current" pid=4036 comm="webapp-containe" requested_mask="r" denied_mask="r" fsuid=1000 ouid=1000
Feb 23 21:07:48 patsdragon kernel: audit: type=1400 audit(1487884068.074:3251): apparmor="DENIED" operation="open" profile="snap.testdemo.testdemo" name="/proc/4036/attr/current" pid=4036 comm="webapp-containe" requested_mask="r" denied_mask="r" fsuid=1000 ouid=1000

[Jamie Strandboge (jdstrand)]

This is committed to master and will be fixed in snapd 2.23.