Dexmaker: Update attachJvmtiAgent API use

Pass the classloader to attachJvmtiAgent. Remove agent extraction code.

Bug: 65016018
Bug: 70901841
Test: mmma external/dexmaker
Test: cts-tradefed run singleCommand cts-dev -m CtsInlineMockingTestCases
Change-Id: I2be3ac3218c11f2ccf9a675fffd35f4fab548070