Update documentation with minimum permissions required to run B&A

[chasinandrew]

Update the documentation in the GCP guide to include the minimum permissions required on the instance service account to run B&A.

Minimum role: roles/compute.viewer
Minimum permissions:

artifactregistry.repositories.downloadArtifacts
artifactregistry.repositories.uploadArtifacts
certificatemanager.certmaps.use
compute.autoscalers.create
compute.autoscalers.delete
compute.autoscalers.get
compute.backendServices.create
compute.backendServices.delete
compute.backendServices.get
compute.backendServices.use
compute.disks.create
compute.firewalls.create
compute.firewalls.delete
compute.firewalls.get
compute.globalAddresses.create
compute.globalAddresses.delete
compute.globalAddresses.get
compute.globalAddresses.use
compute.globalForwardingRules.create
compute.globalForwardingRules.delete
compute.globalForwardingRules.get
compute.globalForwardingRules.setLabels
compute.globalOperations.get
compute.healthChecks.create
compute.healthChecks.delete
compute.healthChecks.get
compute.healthChecks.use
compute.healthChecks.useReadOnly
compute.instanceGroupManagers.create
compute.instanceGroupManagers.delete
compute.instanceGroupManagers.get
compute.instanceGroupManagers.use
compute.instanceGroups.delete
compute.instanceGroups.use
compute.instances.create
compute.instances.get
compute.instances.list
compute.instances.setLabels
compute.instances.setMetadata
compute.instances.setTags
compute.instanceTemplates.create
compute.instanceTemplates.delete
compute.instanceTemplates.get
compute.instanceTemplates.useReadOnly
compute.networks.create
compute.networks.delete
compute.networks.get
compute.networks.updatePolicy
compute.regionOperations.get
compute.routers.create
compute.routers.delete
compute.routers.get
compute.routers.update
compute.sslCertificates.create
compute.sslCertificates.delete
compute.sslCertificates.get
compute.subnetworks.create
compute.subnetworks.delete
compute.subnetworks.get
compute.subnetworks.use
compute.subnetworks.useExternalIp
compute.targetHttpsProxies.create
compute.targetHttpsProxies.delete
compute.targetHttpsProxies.get
compute.targetHttpsProxies.use
compute.targetTcpProxies.create
compute.targetTcpProxies.delete
compute.targetTcpProxies.get
compute.targetTcpProxies.use
compute.urlMaps.create
compute.urlMaps.delete
compute.urlMaps.get
compute.urlMaps.use
confidentialcomputing.challenges.create
confidentialcomputing.challenges.verify
confidentialcomputing.locations.get
dns.changes.create
dns.changes.get
dns.resourceRecordSets.create
dns.resourceRecordSets.delete
dns.resourceRecordSets.list
iam.serviceAccounts.actAs
logging.logEntries.create
monitoring.dashboards.create
monitoring.dashboards.delete
monitoring.dashboards.get
monitoring.metricDescriptors.create
monitoring.timeSeries.create
networkservices.grpcRoutes.create
networkservices.grpcRoutes.delete
networkservices.grpcRoutes.get
networkservices.meshes.create
networkservices.meshes.delete
networkservices.meshes.get
networkservices.meshes.use
networkservices.operations.get
resourcemanager.projects.get
secretmanager.secrets.create
secretmanager.secrets.delete
secretmanager.secrets.get
secretmanager.versions.add
secretmanager.versions.destroy
secretmanager.versions.enable
secretmanager.versions.get
trafficdirector.networks.getConfigs
trafficdirector.networks.reportMetrics