fix(🤖): disable the optional PartitionAlloc dependency for Android

[wcandillon]

We are unable to link Skia Graphite on Android if dawn_partition_alloc_dir is set. We also were unable to unset it via the command line. See discussion at https://groups.google.com/g/dawn-graphics/c/3GM3ZNKzFv0

[skia-codereview-bot]

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