Applying patch for LIBRARIES-2720

[neelkanth-kaushik]

This pull request adds support for serializing and deserializing Java Instant objects as ISO8601-formatted strings using Gson. The main changes include introducing a new adapter for Instant, updating the Gson configuration to use this adapter, and making related utility and import changes.

Support for ISO8601 serialization/deserialization of Instant:

• Added a new ISO8601InstantAdapter class that implements both JsonSerializer and JsonDeserializer for Instant, enabling conversion between Instant objects and ISO8601 strings for Gson serialization and deserialization.
• Registered the new ISO8601InstantAdapter with the GsonBuilder in the Analytics class, so all Instant fields are now handled automatically.
• Imported Instant and the new adapter in Analytics.java to support the new functionality.

Utility enhancements:

• Added a format(Instant instant) method to Iso8601Utils to provide ISO8601 formatting for Instant objects (currently returns epoch seconds as a string; may need enhancement for full ISO8601 compliance).
• Updated imports in Iso8601Utils.java to include Instant.