Improve coverage for j.l.i.ConstantCallSite

Adds coverage for:

ConstantCallSite(java.lang.invoke.MethodType, java.lang.invoke.MethodHandle)

Bug: 182166070
Test: atest core-tests:libcore.java.lang.invoke.CallSitesTest
Merged-In: I3eb21a2420168bdd59ac1671c2771f0f7ef416f3
Change-Id: I3eb21a2420168bdd59ac1671c2771f0f7ef416f3
1 file changed