Check for (and clear) Exceptions thrown by TransferParameters

In GraphicsJNI::getColorSpace, which returns an
android.graphics.ColorSpace for a Bitmap, Skia reads the encoded
transfer function which then gets passed to the TransferParameters
constructor. It's possible for that constructor to throw an Exception,
in which case we cannot call JNI functions without handling the
Exception. Clear it and return null, since we are now unable to create
an android.graphics.ColorSpace.

Bug: 198155681
Test: I805aba8c078aac71d92ea71a199c2e1fe52df8fd
Flag: EXEMPT trivial bug fix
Change-Id: Ib1f7cbcc62a4722a2379b111838584cc4b6a36cc