Update Android NDK version to 15c. (#243)

diff --git a/buildkite/install-android-sdk.sh b/buildkite/install-android-sdk.sh
index 399e7ef..7de287d 100755
--- a/buildkite/install-android-sdk.sh
+++ b/buildkite/install-android-sdk.sh
@@ -16,7 +16,7 @@
 
 # Android NDK
 cd /opt
-curl -sSLo android-ndk.zip https://dl.google.com/android/repository/android-ndk-r14b-linux-x86_64.zip
+curl -sSLo android-ndk.zip https://dl.google.com/android/repository/android-ndk-r15c-linux-x86_64.zip
 unzip android-ndk.zip > /dev/null
 rm android-ndk.zip
 
diff --git a/buildkite/install-buildkite-agent.sh b/buildkite/install-buildkite-agent.sh
index 03a8b2d..d743878 100755
--- a/buildkite/install-buildkite-agent.sh
+++ b/buildkite/install-buildkite-agent.sh
@@ -45,7 +45,7 @@
 set -eu
 
 export ANDROID_HOME="/opt/android-sdk-linux"
-export ANDROID_NDK_HOME="/opt/android-ndk-r14b"
+export ANDROID_NDK_HOME="/opt/android-ndk-r15c"
 export BUILDKITE_ARTIFACT_UPLOAD_DESTINATION="gs://bazel-buildkite-artifacts/$BUILDKITE_JOB_ID"
 export BUILDKITE_GS_ACL="publicRead"
 EOF
diff --git a/buildkite/setup-windows-manual.ps1 b/buildkite/setup-windows-manual.ps1
index 726275a..7f19930 100755
--- a/buildkite/setup-windows-manual.ps1
+++ b/buildkite/setup-windows-manual.ps1
@@ -190,15 +190,15 @@
 $env:PATH = [Environment]::GetEnvironmentVariable("PATH", "Machine") + ";c:\bazel"

 [Environment]::SetEnvironmentVariable("PATH", $env:PATH, "Machine")

 

-## Download the Android NDK and install into C:\android-ndk-r14b.

-$android_ndk_url = "https://dl.google.com/android/repository/android-ndk-r14b-windows-x86_64.zip"

+## Download the Android NDK and install into C:\android-ndk-r15c.

+$android_ndk_url = "https://dl.google.com/android/repository/android-ndk-r15c-windows-x86_64.zip"

 $android_ndk_zip = "c:\temp\android_ndk.zip"

 $android_ndk_root = "c:\android_ndk"

 New-Item $android_ndk_root -ItemType "directory" -Force

 (New-Object Net.WebClient).DownloadFile($android_ndk_url, $android_ndk_zip)

 [System.IO.Compression.ZipFile]::ExtractToDirectory($android_ndk_zip, $android_ndk_root)

-Rename-Item "${android_ndk_root}\android-ndk-r14b" -NewName "r14b"

-[Environment]::SetEnvironmentVariable("ANDROID_NDK_HOME", "${android_ndk_root}\r14b", "Machine")

+Rename-Item "${android_ndk_root}\android-ndk-r15c" -NewName "r15c"

+[Environment]::SetEnvironmentVariable("ANDROID_NDK_HOME", "${android_ndk_root}\r15c", "Machine")

 $env:ANDROID_NDK_HOME = [Environment]::GetEnvironmentVariable("ANDROID_NDK_HOME", "Machine")

 Remove-Item $android_ndk_zip

 

diff --git a/buildkite/setup-windows.ps1 b/buildkite/setup-windows.ps1
index dd145ca..1cfb3d9 100755
--- a/buildkite/setup-windows.ps1
+++ b/buildkite/setup-windows.ps1
@@ -189,15 +189,15 @@
 $env:PATH = [Environment]::GetEnvironmentVariable("PATH", "Machine") + ";c:\bazel"

 [Environment]::SetEnvironmentVariable("PATH", $env:PATH, "Machine")

 

-## Download the Android NDK and install into C:\android-ndk-r14b.

-$android_ndk_url = "https://dl.google.com/android/repository/android-ndk-r14b-windows-x86_64.zip"

+## Download the Android NDK and install into C:\android-ndk-r15c.

+$android_ndk_url = "https://dl.google.com/android/repository/android-ndk-r15c-windows-x86_64.zip"

 $android_ndk_zip = "c:\temp\android_ndk.zip"

 $android_ndk_root = "c:\android_ndk"

 New-Item $android_ndk_root -ItemType "directory" -Force

 (New-Object Net.WebClient).DownloadFile($android_ndk_url, $android_ndk_zip)

 [System.IO.Compression.ZipFile]::ExtractToDirectory($android_ndk_zip, $android_ndk_root)

-Rename-Item "${android_ndk_root}\android-ndk-r14b" -NewName "r14b"

-[Environment]::SetEnvironmentVariable("ANDROID_NDK_HOME", "${android_ndk_root}\r14b", "Machine")

+Rename-Item "${android_ndk_root}\android-ndk-r15c" -NewName "r15c"

+[Environment]::SetEnvironmentVariable("ANDROID_NDK_HOME", "${android_ndk_root}\r15c", "Machine")

 $env:ANDROID_NDK_HOME = [Environment]::GetEnvironmentVariable("ANDROID_NDK_HOME", "Machine")

 Remove-Item $android_ndk_zip