Restore the AMP privacy exception as an option. (prebid#1311)

* Restore the AMP privacy exception as an option.

* Adds missing test case

* More PR feedback

* Remove unused constant

* Comment tweak

Author: hhhjort

endpoints/auction_test.go

@@ -458,6 +458,10 @@ func (m *auctionMockPermissions) PersonalInfoAllowed(ctx context.Context, bidder
 	return m.allowPI, m.allowGeo, m.allowID, nil
 }
 
+func (m *auctionMockPermissions) AMPException() bool {
+	return false
+}
+
 func TestBidSizeValidate(t *testing.T) {
 	bids := make(pbs.PBSBidSlice, 0)
 	// bid1 will be rejected due to undefined size when adunit has multiple sizes

endpoints/cookie_sync_test.go

@@ -257,3 +257,7 @@ func (g *gdprPerms) BidderSyncAllowed(ctx context.Context, bidder openrtb_ext.Bi
 func (g *gdprPerms) PersonalInfoAllowed(ctx context.Context, bidder openrtb_ext.BidderName, PublisherID string, gdprSignal gdpr.Signal, consent string, weakVendorEnforcement bool) (bool, bool, bool, error) {
 	return true, true, true, nil
 }
+
+func (g *gdprPerms) AMPException() bool {
+	return false
+}

endpoints/setuid_test.go

@@ -443,6 +443,10 @@ func (g *mockPermsSetUID) PersonalInfoAllowed(ctx context.Context, bidder openrt
 	return g.allowPI, g.allowPI, g.allowPI, nil
 }
 
+func (g *mockPermsSetUID) AMPException() bool {
+	return false
+}
+
 func newFakeSyncer(familyName string) usersync.Usersyncer {
 	return fakeSyncer{
 		familyName: familyName,

gdpr/impl.go

@@ -101,6 +101,10 @@ func (p *permissionsImpl) normalizeGDPR(gdprSignal Signal) Signal {
 	return SignalYes
 }
 
+func (p *permissionsImpl) AMPException() bool {
+	return p.cfg.AMPException
+}
+
 func (p *permissionsImpl) allowSync(ctx context.Context, vendorID uint16, consent string) (bool, error) {
 
 	if consent == "" {
@@ -283,3 +287,7 @@ func (a AlwaysFail) BidderSyncAllowed(ctx context.Context, bidder openrtb_ext.Bi
 func (a AlwaysFail) PersonalInfoAllowed(ctx context.Context, bidder openrtb_ext.BidderName, PublisherID string, gdprSignal Signal, consent string, weakVendorEnforcement bool) (bool, bool, bool, error) {
 	return false, false, false, nil
 }
+
+func (a AlwaysAllow) AMPException() bool {
+	return false
+}