Revert "Add --parcelable-to-string option to aidl compiler"

This reverts commit 8954a0ee7faa660f9f1d615d22ce2e4af3d5a5cd.

Reason: toString() is generated for parcelable/union/enum for the
C++/NDK backends. For the Java backend, @JavaDerive(toString=true)
annotation can be used to generate toString() method.

Bug: 134658111
Test: aidl_integration_test / aidl_unittests
Change-Id: I4878821773beff0df3bc5305f3217ca995bfd609
3 files changed