RFR: 8342461: Remove calls to doPrivileged in javafx.web/{android, ios}

[Jose Pereda]

Removes `doPrivileged` remaining calls in the `javafx.web` module included in {android,ios} code.

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Commit messages:
 - Remove calls to doPrivileged in javafx.web for android and ios

Changes: https://git.openjdk.org/jfx/pull/1651/files
  Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1651&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8342461
  Stats: 110 lines in 7 files changed: 0 ins; 92 del; 18 mod
  Patch: https://git.openjdk.org/jfx/pull/1651.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1651/head:pull/1651

PR: https://git.openjdk.org/jfx/pull/1651