Merge "Unmap shared memory when no longer used" into pi-dev

void CryptoHal::clearHeapBase(int32_t seqNum) {

    Mutex::Autolock autoLock(mLock);

    /*

     * Clear the remote shared memory mapping by setting the shared

     * buffer base to a null hidl_memory.

     *

     * TODO: Add a releaseSharedBuffer method in a future DRM HAL

     * API version to make this explicit.

     */

    uint32_t bufferId = mHeapBases.valueFor(seqNum).getBufferId();

    Return<void> hResult = mPlugin->setSharedBufferBase(hidl_memory(), bufferId);

    ALOGE_IF(!hResult.isOk(), "setSharedBufferBase(): remote call failed");

    mHeapBases.removeItem(seqNum);

}