Fix Android NDK probe for NDKs older than r11
Fix Android NDK probe for NDKs older than r11

Make sure we continue after the r11 check fails.
Fix the file extension of RELEASE.TXT.
Fix the regular expression that failed for "r10e-rc4 (64-bit)".

Change-Id: I77806350b6951ca49dfb84b5cb4369e788eeaae9
Reviewed-by: Christian Kandeler <3aa99dcdd3f0cac61fb81c2a11771c0cc2497607@qt.io>

qtproject/qt-labs-qbs,qtproject/qt-labs-qbs,qt-labs/qbs,qtproject/qt-labs-qbs,qtproject/qt-labs-qbs,qtproject/qt-labs-qbs,qtproject/qt-labs-qbs,qt-labs/qbs,qtproject/qt-labs-qbs,qt-labs/qbs,qt-labs/qbs,qt-labs/qbs,qt-labs/qbs,qt-labs/qbs