libmeminfo: add API to read ION heap and pool allocation sizes

Add APIs to read sysfs nodes exposed by ION driver.

Bug: 138148041
Test: dumpsys meminfo
Test: libmeminfo_test
Change-Id: I1217e5cea037346066120f7037a39aa6e73bb503
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
3 files changed