Bump Security String to 2019-09-05

Implemented:
============
CVE:            References:  Type:  Severity:  Updated AOSP versions:
CVE-2019-2115   A-129768470  EoP    High       7.1.1, 7.1.2, 8.0, 8.1, 9
CVE-2019-2123   A-34175893   EoP    High       7.1.1, 7.1.2, 8.0, 8.1, 9
CVE-2019-2124   A-127320867  ID     High       7.1.1, 7.1.2, 8.0, 8.1, 9
CVE-2019-2174   A-132927376  EoP    High       7.1.1, 7.1.2, 8.0, 8.1, 9
CVE-2019-2177   A-132456322  RCE    High       7.1.1, 7.1.2, 8.0, 8.1, 9
CVE-2019-2178   A-124462242  EoP    High       7.1.1, 7.1.2, 8.0, 8.1, 9
CVE-2019-2179   A-126200054  ID     High       7.1.1, 7.1.2, 8.0, 8.1, 9

Not Implemented:
================
None

Not Applicable (platform source):
===============
CVE:            References:  Type:  Severity:  Updated AOSP versions:
CVE-2019-2103   A-120610669  ID     High       9
CVE-2019-2108   A-130025324  RCE    Critical   10
CVE-2019-2175   A-135551349  EoP    High       9
CVE-2019-2176   A-134420911  RCE    Critical   8.0, 8.1, 9
CVE-2019-2180   A-110899492  ID     High       8.0, 8.1, 9
CVE-2019-9254   A-130164289  EoP    High       10

Change-Id: I554962ea4c994203db932079db78dc9c07444d44