Remove underlying network caps

This change removes unused fields in the persistable bundle and
VcnGatewayConnectionConfig classes to ensure future flexibility.

Bug: 182219992
Test: atest FrameworksVcnTests
Change-Id: Ic2fec8a87fd19a1780333c61759c4092598d349e
Merged-In: Ic2fec8a87fd19a1780333c61759c4092598d349e
(cherry picked from commit 1f06b95c)