Fix #2582, Cast to unsigned int

[tandharia]

Checklist (Please check before submitting)

• I reviewed the Contributing Guide.
• I signed and emailed the appropriate Contributor License Agreement to [email protected] and copied [email protected].

Describe the contribution

Fixes #2582

• cfe_msg_sechdr_time.c promotes the byte (unsigned char) to a signed integer before the shift operation, which can cause overflow on a 32-bit machine.
• Modified the code to cast the bytes to unsigned integers before performing the shift operations to avoid overflow issues.

Testing performed

Unit Testing

Expected behavior changes

Reduced risk of overflow-related bugs.

System(s) tested on

OS: Ubuntu 18.04

Contributor Info - All information REQUIRED for consideration of pull request

Tvisha Andharia - GSFC 582 intern

[dzbaker]

CCB 1 Aug 2024: Approved pending workflow runs and replacing "unsigned int" with "uint32".

[jphickey]

Suggest using uint32 instead of unsigned int here, as int can be 16 bits.