Canonicalize filepaths before saving to db.

Bug: 126888145
Bug: 122475235
Test: atest DownloadProviderTests
Test: atest cts/tests/app/src/android/app/cts/DownloadManagerTest.java

Change-Id: I96fa73d3a18e94986043c45dc4e12a47d62eeea6
2 files changed