[semantic conventions] add alibaba cloud as a cloud provider

[legendecas]

Changes

Add Alibaba Cloud as one of the cloud providers. So that SDK implementations with the generated definition can start working on detector support, etc.

Alibaba Cloud has ~10% of the global market share, ranking third in the world and first in Asia-Pacific.

Related issues open-telemetry/opentelemetry-js#2378

[Oberon00]

Thank you for the PR!
I think you probably also want to update the faas.invoked_provider trace semantic convention.

EDIT: See here:

opentelemetry-specification/semantic_conventions/trace/faas.yaml

Lines 153 to 171 in 3422558

	- id: invoked_provider
	type:
	allow_custom_values: true
	members:
	- id: AWS
	value: 'aws'
	brief: 'Amazon Web Services'
	- id: Azure
	value: 'azure'
	brief: 'Microsoft Azure'
	- id: GCP
	value: 'gcp'
	brief: 'Google Cloud Platform'
	required: always
	brief: >
	The cloud provider of the invoked function.
	note: >
	SHOULD be equal to the `cloud.provider` resource attribute of the
	invoked function.

(note that there is an open tooling issue for sharing enum definitions: open-telemetry/build-tools#32, but I doesn't look like it will be resolved in the foreseeable future)

[arminru]

Thanks! Please also add an entry in CHANGELOG.md for your addition.

[legendecas]

Just pushed to trigger unresponsive EasyCLA to re-check.