Update Freeze transaction to use instant in time

[ljianghedera]

Problem

Use startTime of Instant to specify freeze transaction start.

Solution

Need to make the following change of the FreezeTransactionBody:

message FreezeTransactionBody {
    int32 startHour = 1 [deprecated = true]; // The start hour (in UTC time), a value between 0 and 23
    int32 startMin = 2 [deprecated = true]; // The start minute (in UTC time), a value between 0 and 59
    int32 endHour = 3 [deprecated = true]; // The end hour (in UTC time), a value between 0 and 23
    int32 endMin = 4 [deprecated = true]; // The end minute (in UTC time), a value between 0 and 59
    FileID updateFile = 5; // The ID of the file needs to be updated during a freeze transaction
    bytes fileHash = 6; // The hash value of the file, used to verify file content before performing freeze and update
    Timestamp startTime = 7; // the freeze start Timestamp
 }

Alternatives

No response