Upgrade Linux host toolchain from glibc 2.11 to 2.15

Bug: b/73539603
Test: ./toolchain/binutils/build.py --host linux --arch arm
Change-Id: I7cd2706464093e2be058917996b2eb2bb7ce9663
diff --git a/build.py b/build.py
index 04a9930..532178a 100755
--- a/build.py
+++ b/build.py
@@ -112,7 +112,7 @@
         env['MACOSX_DEPLOYMENT_TARGET'] = '10.6'
     elif host == 'linux':
         toolchain = ndk.paths.android_path(
-            'prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.11-4.8')
+            'prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.15-4.8')
         toolchain_prefix = 'x86_64-linux'
     elif is_windows:
         toolchain = ndk.paths.android_path(