Temporary disk partition is not formatted before the first mounting if GPT

**Describe the bug: A clear and concise description of what the bug is.**
When provision a Standard_L32s VM(with temporary disk gpt partition), wala report warning logs at the first mount:
```
2020-02-21T13:59:56.701438Z INFO Daemon GPT detected, finding partitions
2020-02-21T13:59:56.705270Z INFO Daemon Found 1 GPT partition(s).
2020-02-21T13:59:56.707936Z INFO Daemon Mount resource disk [mount -t ext4 /dev/sdb1 /mnt/resource]
2020-02-21T13:59:56.720063Z WARNING Daemon Failed to mount resource disk. Retry mounting after re-reading partition info.
2020-02-21T13:59:56.854583Z WARNING Daemon Failed to mount resource disk. Attempting to format and retry mount. [mount: /mnt/resource: wrong fs type, bad option, bad superblock on /dev/sdb1, missing codepage or helper program, or other error.
]
```

**Distro and WALinuxAgent details (please complete the following information):**
- Distro and Version: RHEL-7.8/8.2
- WALinuxAgent version: WALinuxAgent-2.2.46

**Additional context**
If not gpt, wala can check the partition fs and mkfs before mounting. But if gpt, it only check the partition number but no fs checking.
It doesn't impact the final mounting status. The temporary disk partition can be formatted and mounted after the second try. I'm just wondering why it doesn't mkfs at the beginning. Thanks!

Start by tracing the GPT partition detection and first temporary-disk mount path described in the issue, using the reported logs as the expected sequence. Compare it with the non-GPT path that checks the filesystem. Done means a GPT-partitioned temporary disk is formatted before its first mount, with the initial mount succeeding without the retry warning.

Written by the indexing model from the issue text.