Adapt scaling in combineSignalCplxScale*() to prevent signed integer overflows. am: 773ff1d3e8 am: 1b074faaa8 am: b0d57f7546

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/aac/+/14470257

Change-Id: Ie24da11cb129e00474ec80eda17f2ae08d7a300f