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##### SUMMARY
<!--- Explain the problem briefly below -->
The snapshot module currently only supports storage blob as a creation source, it should
supports managed disk as a creation source. 
##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->
lib/ansible/modules/cloud/azure/azure_rm_snapshot.py
##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
ansible 2.9.0
  config file = None
  configured module search path = [u'/home/haiyuan/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
  ansible python module location = /opt/ansible/local/lib/python2.7/site-packages/ansible
  executable location = /opt/ansible/bin/ansible
  python version = 2.7.12 (default, Oct  8 2019, 14:14:10) [GCC 5.4.0 20160609]
```
EXAMPLES = '''
- name: Create a snapshot by importing an unmanaged blob from the same subscription.
  azure_rm_snapshot:
    resource_group: myResourceGroup
    name: mySnapshot
    location: eastus
    creation_data:
      create_option: Import
      source_uri: 'https://mystorageaccount.blob.core.windows.net/osimages/osimage.vhd'
'''
RETURN = '''
id:
    description:
        - Resource ID.
    returned: always
    type: str
    sample: /subscriptions/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxxx/resourceGroups/myResourceGroup/providers/Microsoft.Compute/snapshots/mySnapshot
'''
import time
import json
import re
from ansible.module_utils.azure_rm_common_ext import AzureRMModuleBaseExt
from ansible.module_utils.azure_rm_common_rest import GenericRestClient
from copy import deepcopy
try:
    from msrestazure.azure_exceptions import CloudError
except ImportError:
    
    pass
class Actions: