fix(onboard): remove extra multiplication of RP to avoid overflow

[danxmoran]

Closes #19884

(As debugged by @stuartcarnie) Retention policies in onboarding requests are already proper time.Durations, so multiplying by an extra time.Hour factor causes the values to be incorrect and potentially overflow.

• CHANGELOG.md updated with a link to the PR (not the Issue)
• Well-formatted commit messages
• Rebased/mergeable
• Tests pass
• http/swagger.yml updated (if modified Go structs or API)
• Feature flagged (if modified API)
• Documentation updated or issue created (provide link to issue/pr)
• Signed CLA (if not already signed)

[stuartcarnie]

Great work, @danxmoran and 💯 for adding tests!

[stuartcarnie]

@danxmoran you will need to update the onboarding unit tests:

service_onboarding_test.go:44: Onboarding: true
        onboarding.go:223: onboarding results are different -got/+want
            diff   (*influxdb.OnboardingResults)(
            - 	&{
            - 		User: &influxdb.User{ID: s"068ec83bbb042000", Name: "admin", Status: "active"},
            - 		Org: &influxdb.Organization{
            - 			ID:   s"7e98146b111fe339",
            - 			Name: "org1",
            - 			CRUDLog: influxdb.CRUDLog{
            - 				CreatedAt: s"2020-11-02 22:46:03.821569357 +0"...,
            - 				UpdatedAt: s"2020-11-02 22:46:03.821569544 +0"...,
            - 			},
            - 		},
            - 		Bucket: &influxdb.Bucket{
            - 			ID:              s"d218c3d8c079ca59",
            - 			OrgID:           s"7e98146b111fe339",
            - 			Name:            "bucket1",
            - 			RetentionPeriod: s"168ns",
            - 			CRUDLog: influxdb.CRUDLog{
            - 				CreatedAt: s"2020-11-02 22:46:03.821641188 +0"...,
            - 				UpdatedAt: s"2020-11-02 22:46:03.821641264 +0"...,
            - 			},
            - 		},
            - 		Auth: &influxdb.Authorization{
            - 			ID:          s"068ec83bcb7ad000",
            - 			Token:       "hA1O0tWXCHxSXdxqu0I25sDw4SEPlwayKmx0mpI833CZpGC2WAIcydbE95ANXnvM"...,
            - 			Status:      "active",
            - 			Description: "admin's Token",
            - 			OrgID:       s"7e98146b111fe339",
            - 			UserID:      s"068ec83bbb042000",
            - 			Permissions: []influxdb.Permission{
            - 				s"read:authorizations", s"write:authorizations", s"read:buckets",
            - 				s"write:buckets", ...,
            - 			},
            - 			CRUDLog: influxdb.CRUDLog{
            - 				CreatedAt: s"2020-11-02 22:46:03.821670074 +0"...,
            - 				UpdatedAt: s"2020-11-02 22:46:03.821670074 +0"...,
            - 			},
            - 		},
            - 	},

[danxmoran]

Note to self: Need to update CHANGELOG as well