Replace canonicalUrl with ampdocUrl in Nielsen analytics

[uniquelygeneric]

Updated Nielsen analytics to utilize ampdocUrl in query param.

[uniquelygeneric]

@alanorozco Could you please restart the Travis job? Thanks!

[alanorozco]

@uniquelygeneric Restarted shards. Current reviewer @calebcordry also has restart powers FYI

[calebcordry]

@uniquelygeneric the test failures are real, can you also update

amphtml/extensions/amp-analytics/0.1/test/vendor-requests.json

Lines 283 to 286 in b338300

	"nielsen": {
	"session": "https://!prefixuaid-linkage.imrworldwide.com/cgi-bin/gn?prd=session&c13=asid,P!apid&sessionId=_client_id___page_view_id_&pingtype=4&enc=false&c61=createtm,_timestamp_&rnd=_random_",
	"cloudapi": "https://!prefixcloudapi.imrworldwide.com/nmapi/v2/!apid/_client_id___page_view_id_/a?b=%7B%22devInfo%22%3A%7B%22devId%22%3A%22_client_id___page_view_id_%22%2C%22apn%22%3A%22!apn%22%2C%22apv%22%3A%22!apv%22%2C%22apid%22%3A%22!apid%22%7D%2C%22metadata%22%3A%7B%22static%22%3A%7B%22type%22%3A%22static%22%2C%22section%22%3A%22!section%22%2C%22assetid%22%3A%22_page_view_id_%22%2C%22segA%22%3A%22!segA%22%2C%22segB%22%3A%22!segB%22%2C%22segC%22%3A%22!segC%22%2C%22adModel%22%3A%220%22%2C%22dataSrc%22%3A%22cms%22%7D%2C%22content%22%3A%7B%7D%2C%22ad%22%3A%7B%7D%7D%2C%22event%22%3A%22playhead%22%2C%22position%22%3A%22_timestamp_%22%2C%22data%22%3A%7B%22hidden%22%3A%22_background_state_%22%2C%22blur%22%3A%22_background_state_%22%2C%22position%22%3A%22_timestamp_%22%7D%2C%22type%22%3A%22static%22%2C%22utc%22%3A%22_timestamp_%22%2C%22index%22%3A%221%22%2C%22pageURL%22%3A%22_canonical_url_%22%7D"
	},

This should fix the broken test. Thanks!

[uniquelygeneric]

@calebcordry whoops, forgot to update there, too. Thanks!

Are we good now?

[calebcordry]

LGTM. Thanks for the continued maintenance of this impl!