PD Encryption at Rest gcp_v2

Feature Request

Is your feature request related to a problem? Please describe:

Currently when gcp_v2 is setup, the strategy currently attempts to load with the aws strategy. If the encryption type doesn't exist (such as for future strategies), it should fail instead of attempting.

Describe the feature you'd like:

PD lacks encryption using the same method as gcp_v2. According to the encryption at rest documentation, the strategy suggests the same encryption methods as the TiKV package are used, but this is not considered the case.

Describe alternatives you've considered:

There is no alternative except disabling encryption. gcp strategy method is not applicable.

Teachability, Documentation, Adoption, Migration Strategy:

Encryption at rest documentation may need updating.