Remove Ubuntu 14.04 support from documentation.

Remove mentions of Ubuntu 14.04, improve other Ubuntu installation steps.

Closes #8654.

PiperOrigin-RevId: 253650687
diff --git a/site/docs/android-instrumentation-test.md b/site/docs/android-instrumentation-test.md
index 4617a2b..88d252e 100644
--- a/site/docs/android-instrumentation-test.md
+++ b/site/docs/android-instrumentation-test.md
@@ -67,7 +67,7 @@
 
 Ensure your environment satisfies the following prerequisites:
 
-- **Linux**. Tested on Ubuntu 14.04, 16.04, and 18.04.
+- **Linux**. Tested on Ubuntu 16.04, and 18.04.
 
 - **Bazel 0.12.0** or later. Verify the version by running `bazel info release`.
 
diff --git a/site/docs/install-ubuntu.md b/site/docs/install-ubuntu.md
index 7182ca4..ea04ed0 100644
--- a/site/docs/install-ubuntu.md
+++ b/site/docs/install-ubuntu.md
@@ -9,7 +9,6 @@
 
 *   18.04 (LTS)
 *   16.04 (LTS)
-*   14.04 (LTS)
 
 Install Bazel on Ubuntu using one of the following methods:
 
@@ -31,10 +30,10 @@
 
 ### Step 1: Install required packages
 
-First, install the prerequisites: `pkg-config`, `zip`, `g++`, `zlib1g-dev`, `unzip`, and `python`.
+First, install the prerequisites: `pkg-config`, `zip`, `g++`, `zlib1g-dev`, `unzip`, and `python3`.
 
 ```bash
-sudo apt-get install pkg-config zip g++ zlib1g-dev unzip python
+sudo apt-get install pkg-config zip g++ zlib1g-dev unzip python3
 ```
 
 ### Step 2: Download Bazel
@@ -67,21 +66,18 @@
 
 You can also add this command to your `~/.bashrc` file.
 
-<h2 id="install-on-ubuntu"> Using Bazel custom APT repository</h2>
+<h2 id="install-on-ubuntu"> Using Bazel's APT repository</h2>
 
-### Step 1: Install the JDK
+### Step 1: Install the JDK (optional)
 
-Install JDK 8:
+If you want to build Java code using Bazel, install a JDK:
 
 ```bash
+# Ubuntu 16.04 (LTS) uses OpenJDK 8 by default:
 sudo apt-get install openjdk-8-jdk
-```
 
-On Ubuntu 14.04 LTS you must use a PPA:
-
-```bash
-sudo add-apt-repository ppa:webupd8team/java
-sudo apt-get update && sudo apt-get install oracle-java8-installer
+# Ubuntu 18.04 (LTS) uses OpenJDK 11 by default:
+sudo apt-get install openjdk-11-jdk
 ```
 
 ### Step 2: Add Bazel distribution URI as a package source