RFR: 8156715: TrustStoreManager does not buffer keystore input stream

[Artur Barashev]

Wrap the FileInputStream into a BufferedInputStream which reduces the number of actual file reads when loading a key store.

-------------

Commit messages:
 - 8156715: TrustStoreManager does not buffer keystore input stream

Changes: https://git.openjdk.org/jdk/pull/25920/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25920&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8156715
  Stats: 3 lines in 1 file changed: 1 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/25920.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25920/head:pull/25920

PR: https://git.openjdk.org/jdk/pull/25920