JDWP: remove unecessary feature checks in tests

Removes checks about features both supported by ART and the RI (see
command VirtualMachine.CapabilitiesNew). These capabilities are:
* canWatchFieldModification
* canWatchFieldAccess
* canGetBytecodes
* canGetOwnedMonitorInfo
* canGetCurrentContendedMonitor
* canGetMonitorInfo
* canUseInstanceFilters
* canGetInstanceInfo
* canGetMonitorFrameInfo

For the other capabilites (not supported by both runtimes), adds
dedicated method in VmMirror class and updates tests to use them.

Bug: 17941560
Change-Id: Idf54eb41fa9557f0a4ec0b7a450d42dbd6564265