Support importing property file with expanded name

This change is to support importing property file with its path
variations.

By substitute its filename with another, it can be used to handle
runtime varying filename within single binary.

Here's an example of usage in property defined file.
    import /odm/build_${ro.boot.product.hardware.sku}.prop

Bug: 132592551
Test: boot a device and checks above example import statement in
    "/odm/build.prop" loading expanded filename correctly

Merged-In: If3fdcf620a5d717e0930b1e4e58261bc8f79ec24
(cherry picked from commit a87c0f99)

Change-Id: If3fdcf620a5d717e0930b1e4e58261bc8f79ec24