ArrayValue unwrap()s its elements only if they support unwrap()
Merge branch 'checkUnwrapBeforeCallingUnwrap' of https://git.soma.salesforce.com/mobileplatform/aura into fabbott/master-pending/checkUnwrap

@rev dchasman@
@bug W-2193376@
Merging origin/fabbott/master-pending/checkUnwrap into master